micrOmega giving unexpected peculiar result

Asked by Satyabrata Mahapatra on 2021-02-22

Dear Prof. Pukhov,
We are working on a project and in recent few days we have experimented a few things using CalcHEP and micrOmega 5.0.8.
We feel that there is a bug in the micrOmega because of which we are getting some unexpected peculiar result in our work. To ascertain the results we have also implemented a Toy Model in calcHEP and we are getting similar results for the Toy Model too.

The Details are given below:

Particles in the Dark Sector:
χ1 , χ2 (Z 2 odd fermions)
Let the corresponding masses are M1 , M2 . Assuming M1 < M2 , χ1 becomes the Dark
Matter candidate. Let these two particles (χ1 and χ2 ) interact with SM Higgs (h) with non-renormalizable
operators.

Conventionally, what one would expect is that with increase in the mass-splitting (∆M ) among the dark-sector particles, we expect the thermally averaged cross-section to decrease and consequently the relic density to increase.

But the results we are getting are opposite of it.
we are puzzled about the following two points:
1) How the thermal averaged annihilation cross-section of χ1 (i.e. χ1 χ1 → h h) depends on
the mass splitting (∆M ) or the NLSP mass (M2 )?

2) Why the thermal averaged annihilation cross-section is increasing instead of decreasing with the increase of the mass-splitting ?

I have already sent an email with the results we are getting.
Waiting for your reply.

Thanks and Regards,
Satyabrata

Question information

Language:
English Edit question
Status:
Solved
For:
CalcHEP Edit question
Assignee:
No assignee Edit question
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Last reply:
Revision history for this message
Alexander Belyaev (alexander.belyaev) said :
#1

Dear Satyabrata,

we need to see your model,
in particular how the couplings of your model are related tot he mass split.

If some couplings in your model are proportional to the mass split, then
the cross section will be proportional to mass-split square.
We need to see you model to answer your question. Description in words
is not enough.

Regards,
Alexander Belyaev

On 22/02/2021 14:15, Satyabrata Mahapatra wrote:
> New question #695692 on CalcHEP:
> https://answers.launchpad.net/calchep/+question/695692
>
> Dear Prof. Pukhov,
> We are working on a project and in recent few days we have experimented a few things using CalcHEP and micrOmega 5.0.8.
> We feel that there is a bug in the micrOmega because of which we are getting some unexpected peculiar result in our work. To ascertain the results we have also implemented a Toy Model in calcHEP and we are getting similar results for the Toy Model too.
>
> The Details are given below:
>
> Particles in the Dark Sector:
> χ1 , χ2 (Z 2 odd fermions)
> Let the corresponding masses are M1 , M2 . Assuming M1 < M2 , χ1 becomes the Dark
> Matter candidate. Let these two particles (χ1 and χ2 ) interact with SM Higgs (h) with non-renormalizable
> operators.
>
> Conventionally, what one would expect is that with increase in the mass-splitting (∆M ) among the dark-sector particles, we expect the thermally averaged cross-section to decrease and consequently the relic density to increase.
>
> But the results we are getting are opposite of it.
> we are puzzled about the following two points:
> 1) How the thermal averaged annihilation cross-section of χ1 (i.e. χ1 χ1 → h h) depends on
> the mass splitting (∆M ) or the NLSP mass (M2 )?
>
> 2) Why the thermal averaged annihilation cross-section is increasing instead of decreasing with the increase of the mass-splitting ?
>
>
> I have already sent an email with the results we are getting.
> Waiting for your reply.
>
> Thanks and Regards,
> Satyabrata
>
>

--
______________________________________________________________________
Prof. Alexander S Belyaev (<email address hidden>)
https://www.hep.phys.soton.ac.uk/content/alexander-belyaev

School of Physics & Astronomy, University of Southampton
Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
.....................................................................
Particle Physics Department, Rutherford Appleton Laboratory
Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
.....................................................................
CERN, CH-1211 Geneva 23, Switzerland
Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
______________________________________________________________________

Revision history for this message
Satyabrata Mahapatra (satyabrata-mahapatra) said :
#2

Respected Prof. Belyaev,
Thank you so much for your prompt response.
Please find the attached notes regarding the toy model we have implemented
and the results.
Also I am attaching the corresponding model files.

Kindly check it and help us resolve this issue.

Thanks and Regards,
Satyabrata
=================================
Satyabrata Mahapatra
Research Scholar,
High Energy Physics Group,
Department of Physics
Indian Institute of Technology, Hyderabad
Phone: +91-7978310701, +91-7205501437
==================================

On Mon, Feb 22, 2021 at 8:00 PM Alexander Belyaev <
<email address hidden>> wrote:

> Your question #695692 on CalcHEP changed:
> https://answers.launchpad.net/calchep/+question/695692
>
> Status: Open => Answered
>
> Alexander Belyaev proposed the following answer:
> Dear Satyabrata,
>
> we need to see your model,
> in particular how the couplings of your model are related tot he mass
> split.
>
> If some couplings in your model are proportional to the mass split, then
> the cross section will be proportional to mass-split square.
> We need to see you model to answer your question. Description in words
> is not enough.
>
> Regards,
> Alexander Belyaev
>
>
> On 22/02/2021 14:15, Satyabrata Mahapatra wrote:
> > New question #695692 on CalcHEP:
> > https://answers.launchpad.net/calchep/+question/695692
> >
> > Dear Prof. Pukhov,
> > We are working on a project and in recent few days we have experimented
> a few things using CalcHEP and micrOmega 5.0.8.
> > We feel that there is a bug in the micrOmega because of which we are
> getting some unexpected peculiar result in our work. To ascertain the
> results we have also implemented a Toy Model in calcHEP and we are getting
> similar results for the Toy Model too.
> >
> > The Details are given below:
> >
> > Particles in the Dark Sector:
> > χ1 , χ2 (Z 2 odd fermions)
> > Let the corresponding masses are M1 , M2 . Assuming M1 < M2 , χ1 becomes
> the Dark
> > Matter candidate. Let these two particles (χ1 and χ2 ) interact with SM
> Higgs (h) with non-renormalizable
> > operators.
> >
> > Conventionally, what one would expect is that with increase in the
> mass-splitting (∆M ) among the dark-sector particles, we expect the
> thermally averaged cross-section to decrease and consequently the relic
> density to increase.
> >
> > But the results we are getting are opposite of it.
> > we are puzzled about the following two points:
> > 1) How the thermal averaged annihilation cross-section of χ1 (i.e. χ1 χ1
> → h h) depends on
> > the mass splitting (∆M ) or the NLSP mass (M2 )?
> >
> > 2) Why the thermal averaged annihilation cross-section is increasing
> instead of decreasing with the increase of the mass-splitting ?
> >
> >
> > I have already sent an email with the results we are getting.
> > Waiting for your reply.
> >
> > Thanks and Regards,
> > Satyabrata
> >
> >
>
> --
> ______________________________________________________________________
> Prof. Alexander S Belyaev (<email address hidden>)
> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>
> School of Physics & Astronomy, University of Southampton
> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
> .....................................................................
> Particle Physics Department, Rutherford Appleton Laboratory
> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
> .....................................................................
> CERN, CH-1211 Geneva 23, Switzerland
> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> ______________________________________________________________________
>
> --
> If this answers your question, please go to the following page to let us
> know that it is solved:
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
>
> If you still need help, you can reply to this email or go to the
> following page to enter your feedback:
> https://answers.launchpad.net/calchep/+question/695692
>
> You received this question notification because you asked the question.
>

--

Disclaimer:- This footer text is to convey that this email is sent by one
of the users of IITH. So, do not mark it as SPAM.

Revision history for this message
Satyabrata Mahapatra (satyabrata-mahapatra) said :
#3

Respected Prof. Belyaev,
This is just a polite reminder about a query that I had asked one week ago.
In our model, though none of the couplings are mass-splitting dependent,
still we are getting results where the thermal averaged cross-section is
increasing with mass-splitting instead of decreasing. Also in the absence
of any co-annihilation vertex in the model, we are still observing that the
thermal averaged cross-section is dependent on the mass-splitting.

I had already sent you the model files to check and help us understand the
problem and resolving it.

I am attaching the same in this mail again.

Waiting for your reply.

Thanks and Regards,
Satyabrata
=================================
Satyabrata Mahapatra
Research Scholar,
High Energy Physics Group,
Department of Physics
Indian Institute of Technology, Hyderabad
Phone: +91-7978310701, +91-7205501437
==================================

On Mon, Feb 22, 2021 at 9:07 PM Satyabrata Mahapatra <
<email address hidden>> wrote:

> Respected Prof. Belyaev,
> Thank you so much for your prompt response.
> Please find the attached notes regarding the toy model we have implemented
> and the results.
> Also I am attaching the corresponding model files.
>
> Kindly check it and help us resolve this issue.
>
> Thanks and Regards,
> Satyabrata
> =================================
> Satyabrata Mahapatra
> Research Scholar,
> High Energy Physics Group,
> Department of Physics
> Indian Institute of Technology, Hyderabad
> Phone: +91-7978310701, +91-7205501437
> ==================================
>
>
> On Mon, Feb 22, 2021 at 8:00 PM Alexander Belyaev <
> <email address hidden>> wrote:
>
>> Your question #695692 on CalcHEP changed:
>> https://answers.launchpad.net/calchep/+question/695692
>>
>> Status: Open => Answered
>>
>> Alexander Belyaev proposed the following answer:
>> Dear Satyabrata,
>>
>> we need to see your model,
>> in particular how the couplings of your model are related tot he mass
>> split.
>>
>> If some couplings in your model are proportional to the mass split, then
>> the cross section will be proportional to mass-split square.
>> We need to see you model to answer your question. Description in words
>> is not enough.
>>
>> Regards,
>> Alexander Belyaev
>>
>>
>> On 22/02/2021 14:15, Satyabrata Mahapatra wrote:
>> > New question #695692 on CalcHEP:
>> > https://answers.launchpad.net/calchep/+question/695692
>> >
>> > Dear Prof. Pukhov,
>> > We are working on a project and in recent few days we have experimented
>> a few things using CalcHEP and micrOmega 5.0.8.
>> > We feel that there is a bug in the micrOmega because of which we are
>> getting some unexpected peculiar result in our work. To ascertain the
>> results we have also implemented a Toy Model in calcHEP and we are getting
>> similar results for the Toy Model too.
>> >
>> > The Details are given below:
>> >
>> > Particles in the Dark Sector:
>> > χ1 , χ2 (Z 2 odd fermions)
>> > Let the corresponding masses are M1 , M2 . Assuming M1 < M2 , χ1
>> becomes the Dark
>> > Matter candidate. Let these two particles (χ1 and χ2 ) interact with SM
>> Higgs (h) with non-renormalizable
>> > operators.
>> >
>> > Conventionally, what one would expect is that with increase in the
>> mass-splitting (∆M ) among the dark-sector particles, we expect the
>> thermally averaged cross-section to decrease and consequently the relic
>> density to increase.
>> >
>> > But the results we are getting are opposite of it.
>> > we are puzzled about the following two points:
>> > 1) How the thermal averaged annihilation cross-section of χ1 (i.e. χ1
>> χ1 → h h) depends on
>> > the mass splitting (∆M ) or the NLSP mass (M2 )?
>> >
>> > 2) Why the thermal averaged annihilation cross-section is increasing
>> instead of decreasing with the increase of the mass-splitting ?
>> >
>> >
>> > I have already sent an email with the results we are getting.
>> > Waiting for your reply.
>> >
>> > Thanks and Regards,
>> > Satyabrata
>> >
>> >
>>
>> --
>> ______________________________________________________________________
>> Prof. Alexander S Belyaev (<email address hidden>)
>> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>>
>> School of Physics & Astronomy, University of Southampton
>> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
>> .....................................................................
>> Particle Physics Department, Rutherford Appleton Laboratory
>> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
>> .....................................................................
>> CERN, CH-1211 Geneva 23, Switzerland
>> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
>> ______________________________________________________________________
>>
>> --
>> If this answers your question, please go to the following page to let us
>> know that it is solved:
>>
>> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
>>
>> If you still need help, you can reply to this email or go to the
>> following page to enter your feedback:
>> https://answers.launchpad.net/calchep/+question/695692
>>
>> You received this question notification because you asked the question.
>>
>

--

Disclaimer:- This footer text is to convey that this email is sent by one
of the users of IITH. So, do not mark it as SPAM.

Revision history for this message
Alexander Belyaev (alexander.belyaev) said :
#4

Dear Satyabrata,

sorry  for slow reply.
In the model you have sent to me
the cross sectio n for χ1 χ1 → h h
does not depend on delM -- the MX1-MX2 mass split.

What makes you think that thermally averaged cross-section
depends on delM

Please give me your concrete numbers and explain how did you calculate them.

Thank you,
Alexander

On 03/03/2021 06:44, Satyabrata Mahapatra wrote:
> *CAUTION:* This e-mail originated outside the University of Southampton.
> Respected Prof. Belyaev,
> This is just a polite reminder about a query that I had asked one week
> ago.
> In our model, though none of the couplings are mass-splitting
> dependent, still we are getting results where the thermal averaged
> cross-section is increasing with mass-splitting instead of decreasing.
> Also in the absence of any co-annihilation vertex in the model, we are
> still observing that the thermal averaged cross-section is dependent
> on the mass-splitting.
>
> I had already sent you the model files to check and help us understand
> the problem and resolving it.
>
> I am attaching the same in this mail again.
>
> Waiting for your reply.
>
> Thanks and Regards,
> Satyabrata
> =================================
> Satyabrata Mahapatra
> Research Scholar,
> High Energy Physics Group,
> Department of Physics
> Indian Institute of Technology, Hyderabad
> Phone: +91-7978310701, +91-7205501437
> ==================================
>
>
> On Mon, Feb 22, 2021 at 9:07 PM Satyabrata Mahapatra
> <<email address hidden> <mailto:<email address hidden>>> wrote:
>
> Respected Prof. Belyaev,
> Thank you so much for your prompt response.
> Please find the attached notes regarding the toy model we have
> implemented and the results.
> Also I am attaching the corresponding model files.
>
> Kindly check it and help us resolve this issue.
>
> Thanks and Regards,
> Satyabrata
> =================================
> Satyabrata Mahapatra
> Research Scholar,
> High Energy Physics Group,
> Department of Physics
> Indian Institute of Technology, Hyderabad
> Phone: +91-7978310701, +91-7205501437
> ==================================
>
>
> On Mon, Feb 22, 2021 at 8:00 PM Alexander Belyaev
> <<email address hidden>
> <mailto:<email address hidden>>> wrote:
>
> Your question #695692 on CalcHEP changed:
> https://answers.launchpad.net/calchep/+question/695692
> <https://answers.launchpad.net/calchep/+question/695692>
>
>     Status: Open => Answered
>
> Alexander Belyaev proposed the following answer:
> Dear Satyabrata,
>
> we need to see your model,
> in particular how the couplings of your model are related tot
> he mass split.
>
> If some couplings in your model are proportional to the mass
> split, then
> the cross section will be proportional to mass-split square.
> We need to see you model to answer your question. Description
> in words
> is not enough.
>
> Regards,
> Alexander Belyaev
>
>
> On 22/02/2021 14:15, Satyabrata Mahapatra wrote:
> > New question #695692 on CalcHEP:
> > https://answers.launchpad.net/calchep/+question/695692
> <https://answers.launchpad.net/calchep/+question/695692>
> >
> > Dear Prof. Pukhov,
> > We are working on a project and in recent few days we have
> experimented a few things using CalcHEP and micrOmega 5.0.8.
> > We feel that there is a bug in the micrOmega because of
> which we are getting some unexpected peculiar result in our
> work. To ascertain the results we have also implemented a Toy
> Model in calcHEP and we are getting similar results for the
> Toy Model too.
> >
> > The Details are  given below:
> >
> > Particles in the Dark Sector:
> > χ1 , χ2 (Z 2 odd fermions)
> > Let the corresponding masses are M1 , M2 . Assuming M1 < M2
> , χ1 becomes the Dark
> > Matter candidate. Let these two particles (χ1 and χ2 )
> interact with SM Higgs (h) with non-renormalizable
> > operators.
> >
> > Conventionally, what one would expect is that with increase
> in the mass-splitting (∆M ) among the dark-sector particles,
> we expect the thermally averaged cross-section to decrease and
> consequently the relic density to increase.
> >
> > But the results we are getting are opposite of it.
> > we are puzzled about the following two points:
> > 1) How the thermal averaged annihilation cross-section of χ1
> (i.e. χ1 χ1 → h h) depends on
> > the mass splitting (∆M ) or the NLSP mass (M2 )?
> >
> > 2) Why the thermal averaged annihilation cross-section is
> increasing instead of decreasing with the increase of the
> mass-splitting ?
> >
> >
> > I have already sent an email with the results we are getting.
> > Waiting for your reply.
> >
> > Thanks and Regards,
> > Satyabrata
> >
> >
>
> --
> ______________________________________________________________________
> Prof. Alexander S Belyaev (<email address hidden>
> <mailto:<email address hidden>>)
> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
>
> School of Physics &  Astronomy, University of Southampton
> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
> .....................................................................
> Particle Physics Department, Rutherford Appleton Laboratory
> Didcot,  OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
> .....................................................................
> CERN, CH-1211 Geneva 23, Switzerland
> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> ______________________________________________________________________
>
> --
> If this answers your question, please go to the following page
> to let us
> know that it is solved:
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
> <https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0>
>
> If you still need help, you can reply to this email or go to the
> following page to enter your feedback:
> https://answers.launchpad.net/calchep/+question/695692
> <https://answers.launchpad.net/calchep/+question/695692>
>
> You received this question notification because you asked the
> question.
>
>
> Disclaimer:- This footer text is to convey that this email is sent by
> one of the users of IITH. So, do not mark it as SPAM.
>

--
______________________________________________________________________
Prof. Alexander S Belyaev (<email address hidden>)
https://www.hep.phys.soton.ac.uk/content/alexander-belyaev

School of Physics & Astronomy, University of Southampton
Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
.....................................................................
Particle Physics Department, Rutherford Appleton Laboratory
Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
.....................................................................
CERN, CH-1211 Geneva 23, Switzerland
Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
______________________________________________________________________

Revision history for this message
Satyabrata Mahapatra (satyabrata-mahapatra) said :
#5

Respected Prof. Belyaev,
I had sent you a note in my first mail where we have shown the results.
I am attaching the same note with this mail. Please refer to it for details.

The thermal averaged cross-sections are calculated using micrOmega( using
the vSigma(T,Beps,fast) routine.).

We expect that the thermal averaged annihilation cross-section (in absence
of all co-annihilation vertices) be independent of mass-splitting and the
effective thermal averaged cross-section ( with all annihilations and
co-annihilations included) should decrease with the increase in
mass-splitting.
But we are getting the opposite results.
The same thing is happening in the model we are working on too. So to
ascertain our results we implemented this toy model.

Please check it and let me know if I am missing anything in understanding
or is there any mistake in the procedure we are following.

Waiting for your reply.

Thanks and Regards,
Satyabrata

=================================
Satyabrata Mahapatra
Research Scholar,
High Energy Physics Group,
Department of Physics
Indian Institute of Technology, Hyderabad
Phone: +91-7978310701, +91-7205501437
==================================

On Wed, Mar 3, 2021 at 2:45 PM Alexander Belyaev <
<email address hidden>> wrote:

> Your question #695692 on CalcHEP changed:
> https://answers.launchpad.net/calchep/+question/695692
>
> Status: Open => Answered
>
> Alexander Belyaev proposed the following answer:
> Dear Satyabrata,
>
> sorry for slow reply.
> In the model you have sent to me
> the cross sectio n for χ1 χ1 → h h
> does not depend on delM -- the MX1-MX2 mass split.
>
> What makes you think that thermally averaged cross-section
> depends on delM
>
> Please give me your concrete numbers and explain how did you calculate
> them.
>
> Thank you,
> Alexander
>
>
> On 03/03/2021 06:44, Satyabrata Mahapatra wrote:
> > *CAUTION:* This e-mail originated outside the University of Southampton.
> > Respected Prof. Belyaev,
> > This is just a polite reminder about a query that I had asked one week
> > ago.
> > In our model, though none of the couplings are mass-splitting
> > dependent, still we are getting results where the thermal averaged
> > cross-section is increasing with mass-splitting instead of decreasing.
> > Also in the absence of any co-annihilation vertex in the model, we are
> > still observing that the thermal averaged cross-section is dependent
> > on the mass-splitting.
> >
> > I had already sent you the model files to check and help us understand
> > the problem and resolving it.
> >
> > I am attaching the same in this mail again.
> >
> > Waiting for your reply.
> >
> > Thanks and Regards,
> > Satyabrata
> > =================================
> > Satyabrata Mahapatra
> > Research Scholar,
> > High Energy Physics Group,
> > Department of Physics
> > Indian Institute of Technology, Hyderabad
> > Phone: +91-7978310701, +91-7205501437
> > ==================================
> >
> >
> > On Mon, Feb 22, 2021 at 9:07 PM Satyabrata Mahapatra
> > <<email address hidden> <mailto:<email address hidden>>> wrote:
> >
> > Respected Prof. Belyaev,
> > Thank you so much for your prompt response.
> > Please find the attached notes regarding the toy model we have
> > implemented and the results.
> > Also I am attaching the corresponding model files.
> >
> > Kindly check it and help us resolve this issue.
> >
> > Thanks and Regards,
> > Satyabrata
> > =================================
> > Satyabrata Mahapatra
> > Research Scholar,
> > High Energy Physics Group,
> > Department of Physics
> > Indian Institute of Technology, Hyderabad
> > Phone: +91-7978310701, +91-7205501437
> > ==================================
> >
> >
> > On Mon, Feb 22, 2021 at 8:00 PM Alexander Belyaev
> > <<email address hidden>
> > <mailto:<email address hidden>>> wrote:
> >
> > Your question #695692 on CalcHEP changed:
> > https://answers.launchpad.net/calchep/+question/695692
> > <https://answers.launchpad.net/calchep/+question/695692>
> >
> > Status: Open => Answered
> >
> > Alexander Belyaev proposed the following answer:
> > Dear Satyabrata,
> >
> > we need to see your model,
> > in particular how the couplings of your model are related tot
> > he mass split.
> >
> > If some couplings in your model are proportional to the mass
> > split, then
> > the cross section will be proportional to mass-split square.
> > We need to see you model to answer your question. Description
> > in words
> > is not enough.
> >
> > Regards,
> > Alexander Belyaev
> >
> >
> > On 22/02/2021 14:15, Satyabrata Mahapatra wrote:
> > > New question #695692 on CalcHEP:
> > > https://answers.launchpad.net/calchep/+question/695692
> > <https://answers.launchpad.net/calchep/+question/695692>
> > >
> > > Dear Prof. Pukhov,
> > > We are working on a project and in recent few days we have
> > experimented a few things using CalcHEP and micrOmega 5.0.8.
> > > We feel that there is a bug in the micrOmega because of
> > which we are getting some unexpected peculiar result in our
> > work. To ascertain the results we have also implemented a Toy
> > Model in calcHEP and we are getting similar results for the
> > Toy Model too.
> > >
> > > The Details are given below:
> > >
> > > Particles in the Dark Sector:
> > > χ1 , χ2 (Z 2 odd fermions)
> > > Let the corresponding masses are M1 , M2 . Assuming M1 < M2
> > , χ1 becomes the Dark
> > > Matter candidate. Let these two particles (χ1 and χ2 )
> > interact with SM Higgs (h) with non-renormalizable
> > > operators.
> > >
> > > Conventionally, what one would expect is that with increase
> > in the mass-splitting (∆M ) among the dark-sector particles,
> > we expect the thermally averaged cross-section to decrease and
> > consequently the relic density to increase.
> > >
> > > But the results we are getting are opposite of it.
> > > we are puzzled about the following two points:
> > > 1) How the thermal averaged annihilation cross-section of χ1
> > (i.e. χ1 χ1 → h h) depends on
> > > the mass splitting (∆M ) or the NLSP mass (M2 )?
> > >
> > > 2) Why the thermal averaged annihilation cross-section is
> > increasing instead of decreasing with the increase of the
> > mass-splitting ?
> > >
> > >
> > > I have already sent an email with the results we are getting.
> > > Waiting for your reply.
> > >
> > > Thanks and Regards,
> > > Satyabrata
> > >
> > >
> >
> > --
> >
> ______________________________________________________________________
> > Prof. Alexander S Belyaev (<email address hidden>
> > <mailto:<email address hidden>>)
> > https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
> > <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
> >
> > School of Physics & Astronomy, University of Southampton
> > Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
> >
> .....................................................................
> > Particle Physics Department, Rutherford Appleton Laboratory
> > Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
> >
> .....................................................................
> > CERN, CH-1211 Geneva 23, Switzerland
> > Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> >
> ______________________________________________________________________
> >
> > --
> > If this answers your question, please go to the following page
> > to let us
> > know that it is solved:
> >
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
> > <
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
> >
> >
> > If you still need help, you can reply to this email or go to the
> > following page to enter your feedback:
> > https://answers.launchpad.net/calchep/+question/695692
> > <https://answers.launchpad.net/calchep/+question/695692>
> >
> > You received this question notification because you asked the
> > question.
> >
> >
> > Disclaimer:- This footer text is to convey that this email is sent by
> > one of the users of IITH. So, do not mark it as SPAM.
> >
>
> --
> ______________________________________________________________________
> Prof. Alexander S Belyaev (<email address hidden>)
> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>
> School of Physics & Astronomy, University of Southampton
> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
> .....................................................................
> Particle Physics Department, Rutherford Appleton Laboratory
> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
> .....................................................................
> CERN, CH-1211 Geneva 23, Switzerland
> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> ______________________________________________________________________
>
> --
> If this answers your question, please go to the following page to let us
> know that it is solved:
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=3
>
> If you still need help, you can reply to this email or go to the
> following page to enter your feedback:
> https://answers.launchpad.net/calchep/+question/695692
>
> You received this question notification because you asked the question.
>

--

Disclaimer:- This footer text is to convey that this email is sent by one
of the users of IITH. So, do not mark it as SPAM.

Revision history for this message
Alexander Belyaev (alexander.belyaev) said :
#6

Thanks a lot,
sorry for missing it.
I see now what you have got.
But I can not reproduce it.
Could you send me the code you have used to get these cross section
behaviour?
I need to see how exactly did you set parameters.
Thank you,
Alexander

On 03/03/2021 09:50, Satyabrata Mahapatra wrote:
> Question #695692 on CalcHEP changed:
> https://answers.launchpad.net/calchep/+question/695692
>
> Status: Answered => Open
>
> Satyabrata Mahapatra is still having a problem:
> Respected Prof. Belyaev,
> I had sent you a note in my first mail where we have shown the results.
> I am attaching the same note with this mail. Please refer to it for details.
>
> The thermal averaged cross-sections are calculated using micrOmega( using
> the vSigma(T,Beps,fast) routine.).
>
> We expect that the thermal averaged annihilation cross-section (in absence
> of all co-annihilation vertices) be independent of mass-splitting and the
> effective thermal averaged cross-section ( with all annihilations and
> co-annihilations included) should decrease with the increase in
> mass-splitting.
> But we are getting the opposite results.
> The same thing is happening in the model we are working on too. So to
> ascertain our results we implemented this toy model.
>
> Please check it and let me know if I am missing anything in understanding
> or is there any mistake in the procedure we are following.
>
> Waiting for your reply.
>
> Thanks and Regards,
> Satyabrata
>
> =================================
> Satyabrata Mahapatra
> Research Scholar,
> High Energy Physics Group,
> Department of Physics
> Indian Institute of Technology, Hyderabad
> Phone: +91-7978310701, +91-7205501437
> ==================================
>
>
> On Wed, Mar 3, 2021 at 2:45 PM Alexander Belyaev <
> <email address hidden>> wrote:
>
>> Your question #695692 on CalcHEP changed:
>> https://answers.launchpad.net/calchep/+question/695692
>>
>> Status: Open => Answered
>>
>> Alexander Belyaev proposed the following answer:
>> Dear Satyabrata,
>>
>> sorry for slow reply.
>> In the model you have sent to me
>> the cross sectio n for χ1 χ1 → h h
>> does not depend on delM -- the MX1-MX2 mass split.
>>
>> What makes you think that thermally averaged cross-section
>> depends on delM
>>
>> Please give me your concrete numbers and explain how did you calculate
>> them.
>>
>> Thank you,
>> Alexander
>>
>>
>> On 03/03/2021 06:44, Satyabrata Mahapatra wrote:
>>> *CAUTION:* This e-mail originated outside the University of Southampton.
>>> Respected Prof. Belyaev,
>>> This is just a polite reminder about a query that I had asked one week
>>> ago.
>>> In our model, though none of the couplings are mass-splitting
>>> dependent, still we are getting results where the thermal averaged
>>> cross-section is increasing with mass-splitting instead of decreasing.
>>> Also in the absence of any co-annihilation vertex in the model, we are
>>> still observing that the thermal averaged cross-section is dependent
>>> on the mass-splitting.
>>>
>>> I had already sent you the model files to check and help us understand
>>> the problem and resolving it.
>>>
>>> I am attaching the same in this mail again.
>>>
>>> Waiting for your reply.
>>>
>>> Thanks and Regards,
>>> Satyabrata
>>> =================================
>>> Satyabrata Mahapatra
>>> Research Scholar,
>>> High Energy Physics Group,
>>> Department of Physics
>>> Indian Institute of Technology, Hyderabad
>>> Phone: +91-7978310701, +91-7205501437
>>> ==================================
>>>
>>>
>>> On Mon, Feb 22, 2021 at 9:07 PM Satyabrata Mahapatra
>>> <<email address hidden> <mailto:<email address hidden>>> wrote:
>>>
>>> Respected Prof. Belyaev,
>>> Thank you so much for your prompt response.
>>> Please find the attached notes regarding the toy model we have
>>> implemented and the results.
>>> Also I am attaching the corresponding model files.
>>>
>>> Kindly check it and help us resolve this issue.
>>>
>>> Thanks and Regards,
>>> Satyabrata
>>> =================================
>>> Satyabrata Mahapatra
>>> Research Scholar,
>>> High Energy Physics Group,
>>> Department of Physics
>>> Indian Institute of Technology, Hyderabad
>>> Phone: +91-7978310701, +91-7205501437
>>> ==================================
>>>
>>>
>>> On Mon, Feb 22, 2021 at 8:00 PM Alexander Belyaev
>>> <<email address hidden>
>>> <mailto:<email address hidden>>> wrote:
>>>
>>> Your question #695692 on CalcHEP changed:
>>> https://answers.launchpad.net/calchep/+question/695692
>>> <https://answers.launchpad.net/calchep/+question/695692>
>>>
>>> Status: Open => Answered
>>>
>>> Alexander Belyaev proposed the following answer:
>>> Dear Satyabrata,
>>>
>>> we need to see your model,
>>> in particular how the couplings of your model are related tot
>>> he mass split.
>>>
>>> If some couplings in your model are proportional to the mass
>>> split, then
>>> the cross section will be proportional to mass-split square.
>>> We need to see you model to answer your question. Description
>>> in words
>>> is not enough.
>>>
>>> Regards,
>>> Alexander Belyaev
>>>
>>>
>>> On 22/02/2021 14:15, Satyabrata Mahapatra wrote:
>>> > New question #695692 on CalcHEP:
>>> > https://answers.launchpad.net/calchep/+question/695692
>>> <https://answers.launchpad.net/calchep/+question/695692>
>>> >
>>> > Dear Prof. Pukhov,
>>> > We are working on a project and in recent few days we have
>>> experimented a few things using CalcHEP and micrOmega 5.0.8.
>>> > We feel that there is a bug in the micrOmega because of
>>> which we are getting some unexpected peculiar result in our
>>> work. To ascertain the results we have also implemented a Toy
>>> Model in calcHEP and we are getting similar results for the
>>> Toy Model too.
>>> >
>>> > The Details are given below:
>>> >
>>> > Particles in the Dark Sector:
>>> > χ1 , χ2 (Z 2 odd fermions)
>>> > Let the corresponding masses are M1 , M2 . Assuming M1 < M2
>>> , χ1 becomes the Dark
>>> > Matter candidate. Let these two particles (χ1 and χ2 )
>>> interact with SM Higgs (h) with non-renormalizable
>>> > operators.
>>> >
>>> > Conventionally, what one would expect is that with increase
>>> in the mass-splitting (∆M ) among the dark-sector particles,
>>> we expect the thermally averaged cross-section to decrease and
>>> consequently the relic density to increase.
>>> >
>>> > But the results we are getting are opposite of it.
>>> > we are puzzled about the following two points:
>>> > 1) How the thermal averaged annihilation cross-section of χ1
>>> (i.e. χ1 χ1 → h h) depends on
>>> > the mass splitting (∆M ) or the NLSP mass (M2 )?
>>> >
>>> > 2) Why the thermal averaged annihilation cross-section is
>>> increasing instead of decreasing with the increase of the
>>> mass-splitting ?
>>> >
>>> >
>>> > I have already sent an email with the results we are getting.
>>> > Waiting for your reply.
>>> >
>>> > Thanks and Regards,
>>> > Satyabrata
>>> >
>>> >
>>>
>>> --
>>>
>> ______________________________________________________________________
>>> Prof. Alexander S Belyaev (<email address hidden>
>>> <mailto:<email address hidden>>)
>>> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>>> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
>>>
>>> School of Physics & Astronomy, University of Southampton
>>> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
>>>
>> .....................................................................
>>> Particle Physics Department, Rutherford Appleton Laboratory
>>> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
>>>
>> .....................................................................
>>> CERN, CH-1211 Geneva 23, Switzerland
>>> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
>>>
>> ______________________________________________________________________
>>> --
>>> If this answers your question, please go to the following page
>>> to let us
>>> know that it is solved:
>>>
>> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
>>> <
>> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
>>>
>>> If you still need help, you can reply to this email or go to the
>>> following page to enter your feedback:
>>> https://answers.launchpad.net/calchep/+question/695692
>>> <https://answers.launchpad.net/calchep/+question/695692>
>>>
>>> You received this question notification because you asked the
>>> question.
>>>
>>>
>>> Disclaimer:- This footer text is to convey that this email is sent by
>>> one of the users of IITH. So, do not mark it as SPAM.
>>>
>> --
>> ______________________________________________________________________
>> Prof. Alexander S Belyaev (<email address hidden>)
>> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>>
>> School of Physics & Astronomy, University of Southampton
>> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
>> .....................................................................
>> Particle Physics Department, Rutherford Appleton Laboratory
>> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
>> .....................................................................
>> CERN, CH-1211 Geneva 23, Switzerland
>> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
>> ______________________________________________________________________
>>
>> --
>> If this answers your question, please go to the following page to let us
>> know that it is solved:
>> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=3
>>
>> If you still need help, you can reply to this email or go to the
>> following page to enter your feedback:
>> https://answers.launchpad.net/calchep/+question/695692
>>
>> You received this question notification because you asked the question.
>>
> --
>
>
> Disclaimer:- This footer text is to convey that this email is sent by one
> of the users of IITH. So, do not mark it as SPAM.
>

--
______________________________________________________________________
Prof. Alexander S Belyaev (<email address hidden>)
https://www.hep.phys.soton.ac.uk/content/alexander-belyaev

School of Physics & Astronomy, University of Southampton
Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
.....................................................................
Particle Physics Department, Rutherford Appleton Laboratory
Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
.....................................................................
CERN, CH-1211 Geneva 23, Switzerland
Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
______________________________________________________________________

Revision history for this message
Satyabrata Mahapatra (satyabrata-mahapatra) said :
#7

Respected Sir,
Please find the attached code we used for obtaining the results shown in
the note.
I am using micrOmegas 5.0.8 for the calculation.
Please let us know if you find any mistakes.

Thanks & Regards,
Satyabrata
=================================
Satyabrata Mahapatra
Research Scholar,
High Energy Physics Group,
Department of Physics
Indian Institute of Technology, Hyderabad
Phone: +91-7978310701, +91-7205501437
==================================

On Wed, Mar 3, 2021 at 5:41 PM Alexander Belyaev <
<email address hidden>> wrote:

> Your question #695692 on CalcHEP changed:
> https://answers.launchpad.net/calchep/+question/695692
>
> Status: Open => Answered
>
> Alexander Belyaev proposed the following answer:
> Thanks a lot,
> sorry for missing it.
> I see now what you have got.
> But I can not reproduce it.
> Could you send me the code you have used to get these cross section
> behaviour?
> I need to see how exactly did you set parameters.
> Thank you,
> Alexander
>
>
> On 03/03/2021 09:50, Satyabrata Mahapatra wrote:
> > Question #695692 on CalcHEP changed:
> > https://answers.launchpad.net/calchep/+question/695692
> >
> > Status: Answered => Open
> >
> > Satyabrata Mahapatra is still having a problem:
> > Respected Prof. Belyaev,
> > I had sent you a note in my first mail where we have shown the results.
> > I am attaching the same note with this mail. Please refer to it for
> details.
> >
> > The thermal averaged cross-sections are calculated using micrOmega( using
> > the vSigma(T,Beps,fast) routine.).
> >
> > We expect that the thermal averaged annihilation cross-section (in
> absence
> > of all co-annihilation vertices) be independent of mass-splitting and the
> > effective thermal averaged cross-section ( with all annihilations and
> > co-annihilations included) should decrease with the increase in
> > mass-splitting.
> > But we are getting the opposite results.
> > The same thing is happening in the model we are working on too. So to
> > ascertain our results we implemented this toy model.
> >
> > Please check it and let me know if I am missing anything in understanding
> > or is there any mistake in the procedure we are following.
> >
> > Waiting for your reply.
> >
> > Thanks and Regards,
> > Satyabrata
> >
> > =================================
> > Satyabrata Mahapatra
> > Research Scholar,
> > High Energy Physics Group,
> > Department of Physics
> > Indian Institute of Technology, Hyderabad
> > Phone: +91-7978310701, +91-7205501437
> > ==================================
> >
> >
> > On Wed, Mar 3, 2021 at 2:45 PM Alexander Belyaev <
> > <email address hidden>> wrote:
> >
> >> Your question #695692 on CalcHEP changed:
> >> https://answers.launchpad.net/calchep/+question/695692
> >>
> >> Status: Open => Answered
> >>
> >> Alexander Belyaev proposed the following answer:
> >> Dear Satyabrata,
> >>
> >> sorry for slow reply.
> >> In the model you have sent to me
> >> the cross sectio n for χ1 χ1 → h h
> >> does not depend on delM -- the MX1-MX2 mass split.
> >>
> >> What makes you think that thermally averaged cross-section
> >> depends on delM
> >>
> >> Please give me your concrete numbers and explain how did you calculate
> >> them.
> >>
> >> Thank you,
> >> Alexander
> >>
> >>
> >> On 03/03/2021 06:44, Satyabrata Mahapatra wrote:
> >>> *CAUTION:* This e-mail originated outside the University of
> Southampton.
> >>> Respected Prof. Belyaev,
> >>> This is just a polite reminder about a query that I had asked one week
> >>> ago.
> >>> In our model, though none of the couplings are mass-splitting
> >>> dependent, still we are getting results where the thermal averaged
> >>> cross-section is increasing with mass-splitting instead of decreasing.
> >>> Also in the absence of any co-annihilation vertex in the model, we are
> >>> still observing that the thermal averaged cross-section is dependent
> >>> on the mass-splitting.
> >>>
> >>> I had already sent you the model files to check and help us understand
> >>> the problem and resolving it.
> >>>
> >>> I am attaching the same in this mail again.
> >>>
> >>> Waiting for your reply.
> >>>
> >>> Thanks and Regards,
> >>> Satyabrata
> >>> =================================
> >>> Satyabrata Mahapatra
> >>> Research Scholar,
> >>> High Energy Physics Group,
> >>> Department of Physics
> >>> Indian Institute of Technology, Hyderabad
> >>> Phone: +91-7978310701, +91-7205501437
> >>> ==================================
> >>>
> >>>
> >>> On Mon, Feb 22, 2021 at 9:07 PM Satyabrata Mahapatra
> >>> <<email address hidden> <mailto:<email address hidden>>> wrote:
> >>>
> >>> Respected Prof. Belyaev,
> >>> Thank you so much for your prompt response.
> >>> Please find the attached notes regarding the toy model we have
> >>> implemented and the results.
> >>> Also I am attaching the corresponding model files.
> >>>
> >>> Kindly check it and help us resolve this issue.
> >>>
> >>> Thanks and Regards,
> >>> Satyabrata
> >>> =================================
> >>> Satyabrata Mahapatra
> >>> Research Scholar,
> >>> High Energy Physics Group,
> >>> Department of Physics
> >>> Indian Institute of Technology, Hyderabad
> >>> Phone: +91-7978310701, +91-7205501437
> >>> ==================================
> >>>
> >>>
> >>> On Mon, Feb 22, 2021 at 8:00 PM Alexander Belyaev
> >>> <<email address hidden>
> >>> <mailto:<email address hidden>>> wrote:
> >>>
> >>> Your question #695692 on CalcHEP changed:
> >>> https://answers.launchpad.net/calchep/+question/695692
> >>> <https://answers.launchpad.net/calchep/+question/695692>
> >>>
> >>> Status: Open => Answered
> >>>
> >>> Alexander Belyaev proposed the following answer:
> >>> Dear Satyabrata,
> >>>
> >>> we need to see your model,
> >>> in particular how the couplings of your model are related tot
> >>> he mass split.
> >>>
> >>> If some couplings in your model are proportional to the mass
> >>> split, then
> >>> the cross section will be proportional to mass-split square.
> >>> We need to see you model to answer your question. Description
> >>> in words
> >>> is not enough.
> >>>
> >>> Regards,
> >>> Alexander Belyaev
> >>>
> >>>
> >>> On 22/02/2021 14:15, Satyabrata Mahapatra wrote:
> >>> > New question #695692 on CalcHEP:
> >>> > https://answers.launchpad.net/calchep/+question/695692
> >>> <https://answers.launchpad.net/calchep/+question/695692>
> >>> >
> >>> > Dear Prof. Pukhov,
> >>> > We are working on a project and in recent few days we have
> >>> experimented a few things using CalcHEP and micrOmega 5.0.8.
> >>> > We feel that there is a bug in the micrOmega because of
> >>> which we are getting some unexpected peculiar result in our
> >>> work. To ascertain the results we have also implemented a Toy
> >>> Model in calcHEP and we are getting similar results for the
> >>> Toy Model too.
> >>> >
> >>> > The Details are given below:
> >>> >
> >>> > Particles in the Dark Sector:
> >>> > χ1 , χ2 (Z 2 odd fermions)
> >>> > Let the corresponding masses are M1 , M2 . Assuming M1 < M2
> >>> , χ1 becomes the Dark
> >>> > Matter candidate. Let these two particles (χ1 and χ2 )
> >>> interact with SM Higgs (h) with non-renormalizable
> >>> > operators.
> >>> >
> >>> > Conventionally, what one would expect is that with increase
> >>> in the mass-splitting (∆M ) among the dark-sector particles,
> >>> we expect the thermally averaged cross-section to decrease and
> >>> consequently the relic density to increase.
> >>> >
> >>> > But the results we are getting are opposite of it.
> >>> > we are puzzled about the following two points:
> >>> > 1) How the thermal averaged annihilation cross-section of χ1
> >>> (i.e. χ1 χ1 → h h) depends on
> >>> > the mass splitting (∆M ) or the NLSP mass (M2 )?
> >>> >
> >>> > 2) Why the thermal averaged annihilation cross-section is
> >>> increasing instead of decreasing with the increase of the
> >>> mass-splitting ?
> >>> >
> >>> >
> >>> > I have already sent an email with the results we are
> getting.
> >>> > Waiting for your reply.
> >>> >
> >>> > Thanks and Regards,
> >>> > Satyabrata
> >>> >
> >>> >
> >>>
> >>> --
> >>>
> >> ______________________________________________________________________
> >>> Prof. Alexander S Belyaev (<email address hidden>
> >>> <mailto:<email address hidden>>)
> >>> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
> >>> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
> >>>
> >>> School of Physics & Astronomy, University of Southampton
> >>> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805
> 93910
> >>>
> >> .....................................................................
> >>> Particle Physics Department, Rutherford Appleton Laboratory
> >>> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
> >>>
> >> .....................................................................
> >>> CERN, CH-1211 Geneva 23, Switzerland
> >>> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> >>>
> >> ______________________________________________________________________
> >>> --
> >>> If this answers your question, please go to the following page
> >>> to let us
> >>> know that it is solved:
> >>>
> >>
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
> >>> <
> >>
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
> >>>
> >>> If you still need help, you can reply to this email or go to
> the
> >>> following page to enter your feedback:
> >>> https://answers.launchpad.net/calchep/+question/695692
> >>> <https://answers.launchpad.net/calchep/+question/695692>
> >>>
> >>> You received this question notification because you asked the
> >>> question.
> >>>
> >>>
> >>> Disclaimer:- This footer text is to convey that this email is sent by
> >>> one of the users of IITH. So, do not mark it as SPAM.
> >>>
> >> --
> >> ______________________________________________________________________
> >> Prof. Alexander S Belyaev (<email address hidden>)
> >> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
> >>
> >> School of Physics & Astronomy, University of Southampton
> >> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
> >> .....................................................................
> >> Particle Physics Department, Rutherford Appleton Laboratory
> >> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
> >> .....................................................................
> >> CERN, CH-1211 Geneva 23, Switzerland
> >> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> >> ______________________________________________________________________
> >>
> >> --
> >> If this answers your question, please go to the following page to let us
> >> know that it is solved:
> >>
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=3
> >>
> >> If you still need help, you can reply to this email or go to the
> >> following page to enter your feedback:
> >> https://answers.launchpad.net/calchep/+question/695692
> >>
> >> You received this question notification because you asked the question.
> >>
> > --
> >
> >
> > Disclaimer:- This footer text is to convey that this email is sent by one
> > of the users of IITH. So, do not mark it as SPAM.
> >
>
> --
> ______________________________________________________________________
> Prof. Alexander S Belyaev (<email address hidden>)
> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>
> School of Physics & Astronomy, University of Southampton
> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
> .....................................................................
> Particle Physics Department, Rutherford Appleton Laboratory
> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
> .....................................................................
> CERN, CH-1211 Geneva 23, Switzerland
> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> ______________________________________________________________________
>
> --
> If this answers your question, please go to the following page to let us
> know that it is solved:
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=5
>
> If you still need help, you can reply to this email or go to the
> following page to enter your feedback:
> https://answers.launchpad.net/calchep/+question/695692
>
> You received this question notification because you asked the question.
>

--

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Revision history for this message
Alexander Pukhov (pukhov) said :
#8

Send your model to  <email address hidden>

Launchpad  does not resend attachments.

Best

    Alexander Pukhov

On 3/3/21 4:45 PM, Satyabrata Mahapatra wrote:
> Question #695692 on CalcHEP changed:
> https://answers.launchpad.net/calchep/+question/695692
>
> Status: Answered => Open
>
> Satyabrata Mahapatra is still having a problem:
> Respected Sir,
> Please find the attached code we used for obtaining the results shown in
> the note.
> I am using micrOmegas 5.0.8 for the calculation.
> Please let us know if you find any mistakes.
>
> Thanks & Regards,
> Satyabrata
> =================================
> Satyabrata Mahapatra
> Research Scholar,
> High Energy Physics Group,
> Department of Physics
> Indian Institute of Technology, Hyderabad
> Phone: +91-7978310701, +91-7205501437
> ==================================
>
>
> On Wed, Mar 3, 2021 at 5:41 PM Alexander Belyaev <
> <email address hidden>> wrote:
>
>> Your question #695692 on CalcHEP changed:
>> https://answers.launchpad.net/calchep/+question/695692
>>
>> Status: Open => Answered
>>
>> Alexander Belyaev proposed the following answer:
>> Thanks a lot,
>> sorry for missing it.
>> I see now what you have got.
>> But I can not reproduce it.
>> Could you send me the code you have used to get these cross section
>> behaviour?
>> I need to see how exactly did you set parameters.
>> Thank you,
>> Alexander
>>
>>
>> On 03/03/2021 09:50, Satyabrata Mahapatra wrote:
>>> Question #695692 on CalcHEP changed:
>>> https://answers.launchpad.net/calchep/+question/695692
>>>
>>> Status: Answered => Open
>>>
>>> Satyabrata Mahapatra is still having a problem:
>>> Respected Prof. Belyaev,
>>> I had sent you a note in my first mail where we have shown the results.
>>> I am attaching the same note with this mail. Please refer to it for
>> details.
>>> The thermal averaged cross-sections are calculated using micrOmega( using
>>> the vSigma(T,Beps,fast) routine.).
>>>
>>> We expect that the thermal averaged annihilation cross-section (in
>> absence
>>> of all co-annihilation vertices) be independent of mass-splitting and the
>>> effective thermal averaged cross-section ( with all annihilations and
>>> co-annihilations included) should decrease with the increase in
>>> mass-splitting.
>>> But we are getting the opposite results.
>>> The same thing is happening in the model we are working on too. So to
>>> ascertain our results we implemented this toy model.
>>>
>>> Please check it and let me know if I am missing anything in understanding
>>> or is there any mistake in the procedure we are following.
>>>
>>> Waiting for your reply.
>>>
>>> Thanks and Regards,
>>> Satyabrata
>>>
>>> =================================
>>> Satyabrata Mahapatra
>>> Research Scholar,
>>> High Energy Physics Group,
>>> Department of Physics
>>> Indian Institute of Technology, Hyderabad
>>> Phone: +91-7978310701, +91-7205501437
>>> ==================================
>>>
>>>
>>> On Wed, Mar 3, 2021 at 2:45 PM Alexander Belyaev <
>>> <email address hidden>> wrote:
>>>
>>>> Your question #695692 on CalcHEP changed:
>>>> https://answers.launchpad.net/calchep/+question/695692
>>>>
>>>> Status: Open => Answered
>>>>
>>>> Alexander Belyaev proposed the following answer:
>>>> Dear Satyabrata,
>>>>
>>>> sorry for slow reply.
>>>> In the model you have sent to me
>>>> the cross sectio n for χ1 χ1 → h h
>>>> does not depend on delM -- the MX1-MX2 mass split.
>>>>
>>>> What makes you think that thermally averaged cross-section
>>>> depends on delM
>>>>
>>>> Please give me your concrete numbers and explain how did you calculate
>>>> them.
>>>>
>>>> Thank you,
>>>> Alexander
>>>>
>>>>
>>>> On 03/03/2021 06:44, Satyabrata Mahapatra wrote:
>>>>> *CAUTION:* This e-mail originated outside the University of
>> Southampton.
>>>>> Respected Prof. Belyaev,
>>>>> This is just a polite reminder about a query that I had asked one week
>>>>> ago.
>>>>> In our model, though none of the couplings are mass-splitting
>>>>> dependent, still we are getting results where the thermal averaged
>>>>> cross-section is increasing with mass-splitting instead of decreasing.
>>>>> Also in the absence of any co-annihilation vertex in the model, we are
>>>>> still observing that the thermal averaged cross-section is dependent
>>>>> on the mass-splitting.
>>>>>
>>>>> I had already sent you the model files to check and help us understand
>>>>> the problem and resolving it.
>>>>>
>>>>> I am attaching the same in this mail again.
>>>>>
>>>>> Waiting for your reply.
>>>>>
>>>>> Thanks and Regards,
>>>>> Satyabrata
>>>>> =================================
>>>>> Satyabrata Mahapatra
>>>>> Research Scholar,
>>>>> High Energy Physics Group,
>>>>> Department of Physics
>>>>> Indian Institute of Technology, Hyderabad
>>>>> Phone: +91-7978310701, +91-7205501437
>>>>> ==================================
>>>>>
>>>>>
>>>>> On Mon, Feb 22, 2021 at 9:07 PM Satyabrata Mahapatra
>>>>> <<email address hidden> <mailto:<email address hidden>>> wrote:
>>>>>
>>>>> Respected Prof. Belyaev,
>>>>> Thank you so much for your prompt response.
>>>>> Please find the attached notes regarding the toy model we have
>>>>> implemented and the results.
>>>>> Also I am attaching the corresponding model files.
>>>>>
>>>>> Kindly check it and help us resolve this issue.
>>>>>
>>>>> Thanks and Regards,
>>>>> Satyabrata
>>>>> =================================
>>>>> Satyabrata Mahapatra
>>>>> Research Scholar,
>>>>> High Energy Physics Group,
>>>>> Department of Physics
>>>>> Indian Institute of Technology, Hyderabad
>>>>> Phone: +91-7978310701, +91-7205501437
>>>>> ==================================
>>>>>
>>>>>
>>>>> On Mon, Feb 22, 2021 at 8:00 PM Alexander Belyaev
>>>>> <<email address hidden>
>>>>> <mailto:<email address hidden>>> wrote:
>>>>>
>>>>> Your question #695692 on CalcHEP changed:
>>>>> https://answers.launchpad.net/calchep/+question/695692
>>>>> <https://answers.launchpad.net/calchep/+question/695692>
>>>>>
>>>>> Status: Open => Answered
>>>>>
>>>>> Alexander Belyaev proposed the following answer:
>>>>> Dear Satyabrata,
>>>>>
>>>>> we need to see your model,
>>>>> in particular how the couplings of your model are related tot
>>>>> he mass split.
>>>>>
>>>>> If some couplings in your model are proportional to the mass
>>>>> split, then
>>>>> the cross section will be proportional to mass-split square.
>>>>> We need to see you model to answer your question. Description
>>>>> in words
>>>>> is not enough.
>>>>>
>>>>> Regards,
>>>>> Alexander Belyaev
>>>>>
>>>>>
>>>>> On 22/02/2021 14:15, Satyabrata Mahapatra wrote:
>>>>> > New question #695692 on CalcHEP:
>>>>> > https://answers.launchpad.net/calchep/+question/695692
>>>>> <https://answers.launchpad.net/calchep/+question/695692>
>>>>> >
>>>>> > Dear Prof. Pukhov,
>>>>> > We are working on a project and in recent few days we have
>>>>> experimented a few things using CalcHEP and micrOmega 5.0.8.
>>>>> > We feel that there is a bug in the micrOmega because of
>>>>> which we are getting some unexpected peculiar result in our
>>>>> work. To ascertain the results we have also implemented a Toy
>>>>> Model in calcHEP and we are getting similar results for the
>>>>> Toy Model too.
>>>>> >
>>>>> > The Details are given below:
>>>>> >
>>>>> > Particles in the Dark Sector:
>>>>> > χ1 , χ2 (Z 2 odd fermions)
>>>>> > Let the corresponding masses are M1 , M2 . Assuming M1 < M2
>>>>> , χ1 becomes the Dark
>>>>> > Matter candidate. Let these two particles (χ1 and χ2 )
>>>>> interact with SM Higgs (h) with non-renormalizable
>>>>> > operators.
>>>>> >
>>>>> > Conventionally, what one would expect is that with increase
>>>>> in the mass-splitting (∆M ) among the dark-sector particles,
>>>>> we expect the thermally averaged cross-section to decrease and
>>>>> consequently the relic density to increase.
>>>>> >
>>>>> > But the results we are getting are opposite of it.
>>>>> > we are puzzled about the following two points:
>>>>> > 1) How the thermal averaged annihilation cross-section of χ1
>>>>> (i.e. χ1 χ1 → h h) depends on
>>>>> > the mass splitting (∆M ) or the NLSP mass (M2 )?
>>>>> >
>>>>> > 2) Why the thermal averaged annihilation cross-section is
>>>>> increasing instead of decreasing with the increase of the
>>>>> mass-splitting ?
>>>>> >
>>>>> >
>>>>> > I have already sent an email with the results we are
>> getting.
>>>>> > Waiting for your reply.
>>>>> >
>>>>> > Thanks and Regards,
>>>>> > Satyabrata
>>>>> >
>>>>> >
>>>>>
>>>>> --
>>>>>
>>>> ______________________________________________________________________
>>>>> Prof. Alexander S Belyaev (<email address hidden>
>>>>> <mailto:<email address hidden>>)
>>>>> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>>>>> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
>>>>>
>>>>> School of Physics & Astronomy, University of Southampton
>>>>> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805
>> 93910
>>>> .....................................................................
>>>>> Particle Physics Department, Rutherford Appleton Laboratory
>>>>> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
>>>>>
>>>> .....................................................................
>>>>> CERN, CH-1211 Geneva 23, Switzerland
>>>>> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
>>>>>
>>>> ______________________________________________________________________
>>>>> --
>>>>> If this answers your question, please go to the following page
>>>>> to let us
>>>>> know that it is solved:
>>>>>
>> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
>>>>> <
>> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
>>>>> If you still need help, you can reply to this email or go to
>> the
>>>>> following page to enter your feedback:
>>>>> https://answers.launchpad.net/calchep/+question/695692
>>>>> <https://answers.launchpad.net/calchep/+question/695692>
>>>>>
>>>>> You received this question notification because you asked the
>>>>> question.
>>>>>
>>>>>
>>>>> Disclaimer:- This footer text is to convey that this email is sent by
>>>>> one of the users of IITH. So, do not mark it as SPAM.
>>>>>
>>>> --
>>>> ______________________________________________________________________
>>>> Prof. Alexander S Belyaev (<email address hidden>)
>>>> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>>>>
>>>> School of Physics & Astronomy, University of Southampton
>>>> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
>>>> .....................................................................
>>>> Particle Physics Department, Rutherford Appleton Laboratory
>>>> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
>>>> .....................................................................
>>>> CERN, CH-1211 Geneva 23, Switzerland
>>>> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
>>>> ______________________________________________________________________
>>>>
>>>> --
>>>> If this answers your question, please go to the following page to let us
>>>> know that it is solved:
>>>>
>> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=3
>>>> If you still need help, you can reply to this email or go to the
>>>> following page to enter your feedback:
>>>> https://answers.launchpad.net/calchep/+question/695692
>>>>
>>>> You received this question notification because you asked the question.
>>>>
>>> --
>>>
>>>
>>> Disclaimer:- This footer text is to convey that this email is sent by one
>>> of the users of IITH. So, do not mark it as SPAM.
>>>
>> --
>> ______________________________________________________________________
>> Prof. Alexander S Belyaev (<email address hidden>)
>> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>>
>> School of Physics & Astronomy, University of Southampton
>> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
>> .....................................................................
>> Particle Physics Department, Rutherford Appleton Laboratory
>> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
>> .....................................................................
>> CERN, CH-1211 Geneva 23, Switzerland
>> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
>> ______________________________________________________________________
>>
>> --
>> If this answers your question, please go to the following page to let us
>> know that it is solved:
>> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=5
>>
>> If you still need help, you can reply to this email or go to the
>> following page to enter your feedback:
>> https://answers.launchpad.net/calchep/+question/695692
>>
>> You received this question notification because you asked the question.
>>
> --
>
>
> Disclaimer:- This footer text is to convey that this email is sent by one
> of the users of IITH. So, do not mark it as SPAM.
>

Revision history for this message
Alexander Belyaev (alexander.belyaev) said :
#9

Dear Satyabrata,

I reproduce your results, but there is no mistake neither in your code
not in micrOMEGAs

The point is that
vSigma(tm,Beps,fast) is NORMALISED on the masses of ALL DM particles,
see equation (1) in micrOMEGAs manual.
Normalisation factor is contains the SUM of  K2() functions which falls
with M_X2 increase even if
the cross section of X2 X2->hh is zero. This is because X2 will still
contribute into the thermal equilibrium. So, wehn delta M increasing,
normalisation is decreasing and you have increase in sigmav -- this is
how it is defined.

And the same does
vSigmaCC(tm, newProcess("~x1,~X1 -> h, h"),1)
the sum of all vSigmaCC with the last argument 1 -- give  you
vSigma(tm,Beps,fast)

So, your code and micromegas give the correct result

Best
Alexander

On 03/03/2021 13:40, Satyabrata Mahapatra wrote:
> *CAUTION:* This e-mail originated outside the University of Southampton.
> Respected Sir,
> Please find the attached code we used for obtaining the results shown
> in the note.
> I am using micrOmegas 5.0.8 for the calculation.
> Please let us know if you find any mistakes.
>
> Thanks & Regards,
> Satyabrata
> =================================
> Satyabrata Mahapatra
> Research Scholar,
> High Energy Physics Group,
> Department of Physics
> Indian Institute of Technology, Hyderabad
> Phone: +91-7978310701, +91-7205501437
> ==================================
>
>
> On Wed, Mar 3, 2021 at 5:41 PM Alexander Belyaev
> <<email address hidden>
> <mailto:<email address hidden>>> wrote:
>
> Your question #695692 on CalcHEP changed:
> https://answers.launchpad.net/calchep/+question/695692
> <https://answers.launchpad.net/calchep/+question/695692>
>
>     Status: Open => Answered
>
> Alexander Belyaev proposed the following answer:
> Thanks a lot,
> sorry for missing it.
> I see now what you have got.
> But I can not reproduce it.
> Could you send me the code you have used to get these cross section
> behaviour?
> I need to see how exactly did you set parameters.
> Thank you,
> Alexander
>
>
> On 03/03/2021 09:50, Satyabrata Mahapatra wrote:
> > Question #695692 on CalcHEP changed:
> > https://answers.launchpad.net/calchep/+question/695692
> <https://answers.launchpad.net/calchep/+question/695692>
> >
> >      Status: Answered => Open
> >
> > Satyabrata Mahapatra is still having a problem:
> > Respected Prof. Belyaev,
> > I had sent you a note in my first mail where we have shown the
> results.
> > I am attaching the same note with this mail. Please refer to it
> for details.
> >
> > The thermal averaged cross-sections are calculated using
> micrOmega( using
> > the vSigma(T,Beps,fast) routine.).
> >
> > We expect that the thermal averaged annihilation cross-section
> (in absence
> > of all co-annihilation vertices) be independent of
> mass-splitting and the
> > effective thermal averaged cross-section ( with all
> annihilations and
> > co-annihilations included) should decrease with the increase in
> > mass-splitting.
> > But we are getting the opposite results.
> > The same thing is happening in the model we are working on too.
> So to
> > ascertain our results we implemented this toy model.
> >
> > Please check it and let me know if I am missing anything in
> understanding
> > or is there any mistake in the procedure we are following.
> >
> > Waiting for your reply.
> >
> > Thanks and Regards,
> > Satyabrata
> >
> > =================================
> > Satyabrata Mahapatra
> > Research Scholar,
> > High Energy Physics Group,
> > Department of Physics
> > Indian Institute of Technology, Hyderabad
> > Phone: +91-7978310701, +91-7205501437
> > ==================================
> >
> >
> > On Wed, Mar 3, 2021 at 2:45 PM Alexander Belyaev <
> > <email address hidden>
> <mailto:<email address hidden>>> wrote:
> >
> >> Your question #695692 on CalcHEP changed:
> >> https://answers.launchpad.net/calchep/+question/695692
> <https://answers.launchpad.net/calchep/+question/695692>
> >>
> >>      Status: Open => Answered
> >>
> >> Alexander Belyaev proposed the following answer:
> >> Dear Satyabrata,
> >>
> >> sorry  for slow reply.
> >> In the model you have sent to me
> >> the cross sectio n for χ1 χ1 → h h
> >> does not depend on delM -- the MX1-MX2 mass split.
> >>
> >> What makes you think that thermally averaged cross-section
> >> depends on delM
> >>
> >> Please give me your concrete numbers and explain how did you
> calculate
> >> them.
> >>
> >> Thank you,
> >> Alexander
> >>
> >>
> >> On 03/03/2021 06:44, Satyabrata Mahapatra wrote:
> >>> *CAUTION:* This e-mail originated outside the University of
> Southampton.
> >>> Respected Prof. Belyaev,
> >>> This is just a polite reminder about a query that I had asked
> one week
> >>> ago.
> >>> In our model, though none of the couplings are mass-splitting
> >>> dependent, still we are getting results where the thermal averaged
> >>> cross-section is increasing with mass-splitting instead of
> decreasing.
> >>> Also in the absence of any co-annihilation vertex in the
> model, we are
> >>> still observing that the thermal averaged cross-section is
> dependent
> >>> on the mass-splitting.
> >>>
> >>> I had already sent you the model files to check and help us
> understand
> >>> the problem and resolving it.
> >>>
> >>> I am attaching the same in this mail again.
> >>>
> >>> Waiting for your reply.
> >>>
> >>> Thanks and Regards,
> >>> Satyabrata
> >>> =================================
> >>> Satyabrata Mahapatra
> >>> Research Scholar,
> >>> High Energy Physics Group,
> >>> Department of Physics
> >>> Indian Institute of Technology, Hyderabad
> >>> Phone: +91-7978310701, +91-7205501437
> >>> ==================================
> >>>
> >>>
> >>> On Mon, Feb 22, 2021 at 9:07 PM Satyabrata Mahapatra
> >>> <<email address hidden> <mailto:<email address hidden>>
> <mailto:<email address hidden>
> <mailto:<email address hidden>>>> wrote:
> >>>
> >>>      Respected Prof. Belyaev,
> >>>      Thank you so much for your prompt response.
> >>>      Please find the attached notes regarding the toy model we
> have
> >>>      implemented and the results.
> >>>      Also I am attaching the corresponding model files.
> >>>
> >>>      Kindly check it and help us resolve this issue.
> >>>
> >>>      Thanks and Regards,
> >>>      Satyabrata
> >>>      =================================
> >>>      Satyabrata Mahapatra
> >>>      Research Scholar,
> >>>      High Energy Physics Group,
> >>>      Department of Physics
> >>>      Indian Institute of Technology, Hyderabad
> >>>      Phone: +91-7978310701, +91-7205501437
> >>>      ==================================
> >>>
> >>>
> >>>      On Mon, Feb 22, 2021 at 8:00 PM Alexander Belyaev
> >>>      <<email address hidden>
> <mailto:<email address hidden>>
> >>>      <mailto:<email address hidden>
> <mailto:<email address hidden>>>> wrote:
> >>>
> >>>          Your question #695692 on CalcHEP changed:
> >>> https://answers.launchpad.net/calchep/+question/695692
> <https://answers.launchpad.net/calchep/+question/695692>
> >>>
> <https://answers.launchpad.net/calchep/+question/695692
> <https://answers.launchpad.net/calchep/+question/695692>>
> >>>
> >>>              Status: Open => Answered
> >>>
> >>>          Alexander Belyaev proposed the following answer:
> >>>          Dear Satyabrata,
> >>>
> >>>          we need to see your model,
> >>>          in particular how the couplings of your model are
> related tot
> >>>          he mass split.
> >>>
> >>>          If some couplings in your model are proportional to
> the mass
> >>>          split, then
> >>>          the cross section will be proportional to mass-split
> square.
> >>>          We need to see you model to answer your question.
> Description
> >>>          in words
> >>>          is not enough.
> >>>
> >>>          Regards,
> >>>          Alexander Belyaev
> >>>
> >>>
> >>>          On 22/02/2021 14:15, Satyabrata Mahapatra wrote:
> >>>          > New question #695692 on CalcHEP:
> >>>          >
> https://answers.launchpad.net/calchep/+question/695692
> <https://answers.launchpad.net/calchep/+question/695692>
> >>>
> <https://answers.launchpad.net/calchep/+question/695692
> <https://answers.launchpad.net/calchep/+question/695692>>
> >>>          >
> >>>          > Dear Prof. Pukhov,
> >>>          > We are working on a project and in recent few days
> we have
> >>>          experimented a few things using CalcHEP and micrOmega
> 5.0.8.
> >>>          > We feel that there is a bug in the micrOmega because of
> >>>          which we are getting some unexpected peculiar result
> in our
> >>>          work. To ascertain the results we have also
> implemented a Toy
> >>>          Model in calcHEP and we are getting similar results
> for the
> >>>          Toy Model too.
> >>>          >
> >>>          > The Details are  given below:
> >>>          >
> >>>          > Particles in the Dark Sector:
> >>>          > χ1 , χ2 (Z 2 odd fermions)
> >>>          > Let the corresponding masses are M1 , M2 . Assuming
> M1 < M2
> >>>          , χ1 becomes the Dark
> >>>          > Matter candidate. Let these two particles (χ1 and χ2 )
> >>>          interact with SM Higgs (h) with non-renormalizable
> >>>          > operators.
> >>>          >
> >>>          > Conventionally, what one would expect is that with
> increase
> >>>          in the mass-splitting (∆M ) among the dark-sector
> particles,
> >>>          we expect the thermally averaged cross-section to
> decrease and
> >>>          consequently the relic density to increase.
> >>>          >
> >>>          > But the results we are getting are opposite of it.
> >>>          > we are puzzled about the following two points:
> >>>          > 1) How the thermal averaged annihilation
> cross-section of χ1
> >>>          (i.e. χ1 χ1 → h h) depends on
> >>>          > the mass splitting (∆M ) or the NLSP mass (M2 )?
> >>>          >
> >>>          > 2) Why the thermal averaged annihilation
> cross-section is
> >>>          increasing instead of decreasing with the increase of the
> >>>          mass-splitting ?
> >>>          >
> >>>          >
> >>>          > I have already sent an email with the results we
> are getting.
> >>>          > Waiting for your reply.
> >>>          >
> >>>          > Thanks and Regards,
> >>>          > Satyabrata
> >>>          >
> >>>          >
> >>>
> >>>          --
> >>>
> >>
>  ______________________________________________________________________
> >>>          Prof. Alexander S Belyaev (<email address hidden>
> <mailto:<email address hidden>>
> >>>          <mailto:<email address hidden>
> <mailto:<email address hidden>>>)
> >>> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
> >>>
> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>>
> >>>
> >>>          School of Physics &  Astronomy, University of Southampton
> >>>          Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44
> 23805 93910
> >>>
> >>
>  .....................................................................
> >>>          Particle Physics Department, Rutherford Appleton
> Laboratory
> >>>          Didcot,  OX11 0QX, TEL: +44 12354 45562, FAX: +44
> 12354 46733
> >>>
> >>
>  .....................................................................
> >>>          CERN, CH-1211 Geneva 23, Switzerland
> >>>          Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> >>>
> >>
>  ______________________________________________________________________
> >>>          --
> >>>          If this answers your question, please go to the
> following page
> >>>          to let us
> >>>          know that it is solved:
> >>>
> >>
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
> <https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0>
> >>>          <
> >>
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
> <https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0>
> >>>
> >>>          If you still need help, you can reply to this email
> or go to the
> >>>          following page to enter your feedback:
> >>> https://answers.launchpad.net/calchep/+question/695692
> <https://answers.launchpad.net/calchep/+question/695692>
> >>>
> <https://answers.launchpad.net/calchep/+question/695692
> <https://answers.launchpad.net/calchep/+question/695692>>
> >>>
> >>>          You received this question notification because you
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> >>
> ______________________________________________________________________
> >> Prof. Alexander S Belyaev (<email address hidden>
> <mailto:<email address hidden>>)
> >> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
> >>
> >> School of Physics &  Astronomy, University of Southampton
> >> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
> >>
> .....................................................................
> >> Particle Physics Department, Rutherford Appleton Laboratory
> >> Didcot,  OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
> >>
> .....................................................................
> >> CERN, CH-1211 Geneva 23, Switzerland
> >> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> >>
> ______________________________________________________________________
> >>
> >> --
> >> If this answers your question, please go to the following page
> to let us
> >> know that it is solved:
> >>
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=3
> <https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=3>
> >>
> >> If you still need help, you can reply to this email or go to the
> >> following page to enter your feedback:
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> <mailto:<email address hidden>>)
> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
>
> School of Physics &  Astronomy, University of Southampton
> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
> .....................................................................
> Particle Physics Department, Rutherford Appleton Laboratory
> Didcot,  OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
> .....................................................................
> CERN, CH-1211 Geneva 23, Switzerland
> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> ______________________________________________________________________
>
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--
______________________________________________________________________
Prof. Alexander S Belyaev (<email address hidden>)
https://www.hep.phys.soton.ac.uk/content/alexander-belyaev

School of Physics & Astronomy, University of Southampton
Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
.....................................................................
Particle Physics Department, Rutherford Appleton Laboratory
Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
.....................................................................
CERN, CH-1211 Geneva 23, Switzerland
Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
______________________________________________________________________

Revision history for this message
Alexander Pukhov (pukhov) said :
#10

Dear  Satyabrata Mahapatra,

It is very good that you paid  attention  to  this moment.

Let me explain to you what's going on with one example.  But first of
all  I have a note about normalization factors.

If we have a particle which annihilates with anti-particle, then number
of events in space-time unit is

        N= vsigma*rho^2, where rho - in a number density of particles (
not summary density of particles and antiparticles)

If we have a particle which annihilates with itself then

        N=0.5 vsigma*rho^2

In general  for particle - anti-particle system   we also can expect
reactions  particle,particle->SM,SM and in some models we indeed  see
such reactions.

micrOMEGAs defines  vSigma as

            vSigma =     2* Nevents /(rho_DM)^2

where rho_DM includes both particles and anti-particles, and Nevents
takes into account both particle - anti-particles and particle -
particle annihilation if they take place.

Let we  have 2 particles 1 and 2 which annihilate with their
antiparticles with the same  rates vs. If mass gap is zero, then they
have the same density rho and

rho_DM =4*rho, Nevents=  2*vs*rho^2,  vSigma= 2*vs*rho^2/(16*rho)^2=  vs/8

When we increase mass gap  significantly  the second particle disappears
and we have

rho_DM =2*rho, Nevents=vs*rho^2 , vSigma= vs/4

So, it becomes twice larger, as you observe.

The key point is as  follows. vSigma=vs only  if all pairs of
interaction  ( particle - anti-particle and particle_1 - particle_2)
have the same vs. But in your ( it is the usual ) case many interactions
are absent and we  have   vSigma= vs/8. *When one particle  is avoid by
mass shift then percent of  zero interaction channels   decreases and
vSigma increases. *

If you include 1,(anti) 2 ->SM,SM reaction with the same rate vs, then
vSgma will not depend on mass gap.

I hope it is clear. If not, write me once more and I'll try to find
another words.

Best

    Alexander Pukhov

On 3/3/21 9:01 PM, Alexander Belyaev wrote:
> Question #695692 on CalcHEP changed:
> https://answers.launchpad.net/calchep/+question/695692
>
> Alexander Belyaev proposed the following answer:
> Dear Satyabrata,
>
> I reproduce your results, but there is no mistake neither in your code
> not in micrOMEGAs
>
> The point is that
> vSigma(tm,Beps,fast) is NORMALISED on the masses of ALL DM particles,
> see equation (1) in micrOMEGAs manual.
> Normalisation factor is contains the SUM of  K2() functions which falls
> with M_X2 increase even if
> the cross section of X2 X2->hh is zero. This is because X2 will still
> contribute into the thermal equilibrium. So, wehn delta M increasing,
> normalisation is decreasing and you have increase in sigmav -- this is
> how it is defined.
>
>
> And the same does
> vSigmaCC(tm, newProcess("~x1,~X1 -> h, h"),1)
> the sum of all vSigmaCC with the last argument 1 -- give  you
> vSigma(tm,Beps,fast)
>
> So, your code and micromegas give the correct result
>
> Best
> Alexander
>
>
>
> On 03/03/2021 13:40, Dearwrote:
>> *CAUTION:* This e-mail originated outside the University of Southampton.
>> Respected Sir,
>> Please find the attached code we used for obtaining the results shown
>> in the note.
>> I am using micrOmegas 5.0.8 for the calculation.
>> Please let us know if you find any mistakes.
>>
>> Thanks & Regards,
>> Satyabrata
>> =================================
>> Satyabrata Mahapatra
>> Research Scholar,
>> High Energy Physics Group,
>> Department of Physics
>> Indian Institute of Technology, Hyderabad
>> Phone: +91-7978310701, +91-7205501437
>> ==================================
>>
>>
>> On Wed, Mar 3, 2021 at 5:41 PM Alexander Belyaev
>> <<email address hidden>
>> <mailto:<email address hidden>>> wrote:
>>
>> Your question #695692 on CalcHEP changed:
>> https://answers.launchpad.net/calchep/+question/695692
>> <https://answers.launchpad.net/calchep/+question/695692>
>>
>>     Status: Open => Answered
>>
>> Alexander Belyaev proposed the following answer:
>> Thanks a lot,
>> sorry for missing it.
>> I see now what you have got.
>> But I can not reproduce it.
>> Could you send me the code you have used to get these cross section
>> behaviour?
>> I need to see how exactly did you set parameters.
>> Thank you,
>> Alexander
>>
>>
>> On 03/03/2021 09:50, Satyabrata Mahapatra wrote:
>> > Question #695692 on CalcHEP changed:
>> > https://answers.launchpad.net/calchep/+question/695692
>> <https://answers.launchpad.net/calchep/+question/695692>
>> >
>> >      Status: Answered => Open
>> >
>> > Satyabrata Mahapatra is still having a problem:
>> > Respected Prof. Belyaev,
>> > I had sent you a note in my first mail where we have shown the
>> results.
>> > I am attaching the same note with this mail. Please refer to it
>> for details.
>> >
>> > The thermal averaged cross-sections are calculated using
>> micrOmega( using
>> > the vSigma(T,Beps,fast) routine.).
>> >
>> > We expect that the thermal averaged annihilation cross-section
>> (in absence
>> > of all co-annihilation vertices) be independent of
>> mass-splitting and the
>> > effective thermal averaged cross-section ( with all
>> annihilations and
>> > co-annihilations included) should decrease with the increase in
>> > mass-splitting.
>> > But we are getting the opposite results.
>> > The same thing is happening in the model we are working on too.
>> So to
>> > ascertain our results we implemented this toy model.
>> >
>> > Please check it and let me know if I am missing anything in
>> understanding
>> > or is there any mistake in the procedure we are following.
>> >
>> > Waiting for your reply.
>> >
>> > Thanks and Regards,
>> > Satyabrata
>> >
>> > =================================
>> > Satyabrata Mahapatra
>> > Research Scholar,
>> > High Energy Physics Group,
>> > Department of Physics
>> > Indian Institute of Technology, Hyderabad
>> > Phone: +91-7978310701, +91-7205501437
>> > ==================================
>> >
>> >
>> > On Wed, Mar 3, 2021 at 2:45 PM Alexander Belyaev <
>> > <email address hidden>
>> <mailto:<email address hidden>>> wrote:
>> >
>> >> Your question #695692 on CalcHEP changed:
>> >> https://answers.launchpad.net/calchep/+question/695692
>> <https://answers.launchpad.net/calchep/+question/695692>
>> >>
>> >>      Status: Open => Answered
>> >>
>> >> Alexander Belyaev proposed the following answer:
>> >> Dear Satyabrata,
>> >>
>> >> sorry  for slow reply.
>> >> In the model you have sent to me
>> >> the cross sectio n for χ1 χ1 → h h
>> >> does not depend on delM -- the MX1-MX2 mass split.
>> >>
>> >> What makes you think that thermally averaged cross-section
>> >> depends on delM
>> >>
>> >> Please give me your concrete numbers and explain how did you
>> calculate
>> >> them.
>> >>
>> >> Thank you,
>> >> Alexander
>> >>
>> >>
>> >> On 03/03/2021 06:44, Satyabrata Mahapatra wrote:
>> >>> *CAUTION:* This e-mail originated outside the University of
>> Southampton.
>> >>> Respected Prof. Belyaev,
>> >>> This is just a polite reminder about a query that I had asked
>> one week
>> >>> ago.
>> >>> In our model, though none of the couplings are mass-splitting
>> >>> dependent, still we are getting results where the thermal averaged
>> >>> cross-section is increasing with mass-splitting instead of
>> decreasing.
>> >>> Also in the absence of any co-annihilation vertex in the
>> model, we are
>> >>> still observing that the thermal averaged cross-section is
>> dependent
>> >>> on the mass-splitting.
>> >>>
>> >>> I had already sent you the model files to check and help us
>> understand
>> >>> the problem and resolving it.
>> >>>
>> >>> I am attaching the same in this mail again.
>> >>>
>> >>> Waiting for your reply.
>> >>>
>> >>> Thanks and Regards,
>> >>> Satyabrata
>> >>> =================================
>> >>> Satyabrata Mahapatra
>> >>> Research Scholar,
>> >>> High Energy Physics Group,
>> >>> Department of Physics
>> >>> Indian Institute of Technology, Hyderabad
>> >>> Phone: +91-7978310701, +91-7205501437
>> >>> ==================================
>> >>>
>> >>>
>> >>> On Mon, Feb 22, 2021 at 9:07 PM Satyabrata Mahapatra
>> >>> <<email address hidden> <mailto:<email address hidden>>
>> <mailto:<email address hidden>
>> <mailto:<email address hidden>>>> wrote:
>> >>>
>> >>>      Respected Prof. Belyaev,
>> >>>      Thank you so much for your prompt response.
>> >>>      Please find the attached notes regarding the toy model we
>> have
>> >>>      implemented and the results.
>> >>>      Also I am attaching the corresponding model files.
>> >>>
>> >>>      Kindly check it and help us resolve this issue.
>> >>>
>> >>>      Thanks and Regards,
>> >>>      Satyabrata
>> >>>      =================================
>> >>>      Satyabrata Mahapatra
>> >>>      Research Scholar,
>> >>>      High Energy Physics Group,
>> >>>      Department of Physics
>> >>>      Indian Institute of Technology, Hyderabad
>> >>>      Phone: +91-7978310701, +91-7205501437
>> >>>      ==================================
>> >>>
>> >>>
>> >>>      On Mon, Feb 22, 2021 at 8:00 PM Alexander Belyaev
>> >>>      <<email address hidden>
>> <mailto:<email address hidden>>
>> >>>      <mailto:<email address hidden>
>> <mailto:<email address hidden>>>> wrote:
>> >>>
>> >>>          Your question #695692 on CalcHEP changed:
>> >>> https://answers.launchpad.net/calchep/+question/695692
>> <https://answers.launchpad.net/calchep/+question/695692>
>> >>>
>> <https://answers.launchpad.net/calchep/+question/695692
>> <https://answers.launchpad.net/calchep/+question/695692>>
>> >>>
>> >>>              Status: Open => Answered
>> >>>
>> >>>          Alexander Belyaev proposed the following answer:
>> >>>          Dear Satyabrata,
>> >>>
>> >>>          we need to see your model,
>> >>>          in particular how the couplings of your model are
>> related tot
>> >>>          he mass split.
>> >>>
>> >>>          If some couplings in your model are proportional to
>> the mass
>> >>>          split, then
>> >>>          the cross section will be proportional to mass-split
>> square.
>> >>>          We need to see you model to answer your question.
>> Description
>> >>>          in words
>> >>>          is not enough.
>> >>>
>> >>>          Regards,
>> >>>          Alexander Belyaev
>> >>>
>> >>>
>> >>>          On 22/02/2021 14:15, Satyabrata Mahapatra wrote:
>> >>>          > New question #695692 on CalcHEP:
>> >>>          >
>> https://answers.launchpad.net/calchep/+question/695692
>> <https://answers.launchpad.net/calchep/+question/695692>
>> >>>
>> <https://answers.launchpad.net/calchep/+question/695692
>> <https://answers.launchpad.net/calchep/+question/695692>>
>> >>>          >
>> >>>          > Dear Prof. Pukhov,
>> >>>          > We are working on a project and in recent few days
>> we have
>> >>>          experimented a few things using CalcHEP and micrOmega
>> 5.0.8.
>> >>>          > We feel that there is a bug in the micrOmega because of
>> >>>          which we are getting some unexpected peculiar result
>> in our
>> >>>          work. To ascertain the results we have also
>> implemented a Toy
>> >>>          Model in calcHEP and we are getting similar results
>> for the
>> >>>          Toy Model too.
>> >>>          >
>> >>>          > The Details are  given below:
>> >>>          >
>> >>>          > Particles in the Dark Sector:
>> >>>          > χ1 , χ2 (Z 2 odd fermions)
>> >>>          > Let the corresponding masses are M1 , M2 . Assuming
>> M1 < M2
>> >>>          , χ1 becomes the Dark
>> >>>          > Matter candidate. Let these two particles (χ1 and χ2 )
>> >>>          interact with SM Higgs (h) with non-renormalizable
>> >>>          > operators.
>> >>>          >
>> >>>          > Conventionally, what one would expect is that with
>> increase
>> >>>          in the mass-splitting (∆M ) among the dark-sector
>> particles,
>> >>>          we expect the thermally averaged cross-section to
>> decrease and
>> >>>          consequently the relic density to increase.
>> >>>          >
>> >>>          > But the results we are getting are opposite of it.
>> >>>          > we are puzzled about the following two points:
>> >>>          > 1) How the thermal averaged annihilation
>> cross-section of χ1
>> >>>          (i.e. χ1 χ1 → h h) depends on
>> >>>          > the mass splitting (∆M ) or the NLSP mass (M2 )?
>> >>>          >
>> >>>          > 2) Why the thermal averaged annihilation
>> cross-section is
>> >>>          increasing instead of decreasing with the increase of the
>> >>>          mass-splitting ?
>> >>>          >
>> >>>          >
>> >>>          > I have already sent an email with the results we
>> are getting.
>> >>>          > Waiting for your reply.
>> >>>          >
>> >>>          > Thanks and Regards,
>> >>>          > Satyabrata
>> >>>          >
>> >>>          >
>> >>>
>> >>>          --
>> >>>
>> >>
>>  ______________________________________________________________________
>> >>>          Prof. Alexander S Belyaev (<email address hidden>
>> <mailto:<email address hidden>>
>> >>>          <mailto:<email address hidden>
>> <mailto:<email address hidden>>>)
>> >>> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
>> >>>
>> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>>
>> >>>
>> >>>          School of Physics &  Astronomy, University of Southampton
>> >>>          Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44
>> 23805 93910
>> >>>
>> >>
>>  .....................................................................
>> >>>          Particle Physics Department, Rutherford Appleton
>> Laboratory
>> >>>          Didcot,  OX11 0QX, TEL: +44 12354 45562, FAX: +44
>> 12354 46733
>> >>>
>> >>
>>  .....................................................................
>> >>>          CERN, CH-1211 Geneva 23, Switzerland
>> >>>          Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
>> >>>
>> >>
>>  ______________________________________________________________________
>> >>>          --
>> >>>          If this answers your question, please go to the
>> following page
>> >>>          to let us
>> >>>          know that it is solved:
>> >>>
>> >>
>> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
>> <https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0>
>> >>>          <
>> >>
>> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
>> <https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0>
>> >>>
>> >>>          If you still need help, you can reply to this email
>> or go to the
>> >>>          following page to enter your feedback:
>> >>> https://answers.launchpad.net/calchep/+question/695692
>> <https://answers.launchpad.net/calchep/+question/695692>
>> >>>
>> <https://answers.launchpad.net/calchep/+question/695692
>> <https://answers.launchpad.net/calchep/+question/695692>>
>> >>>
>> >>>          You received this question notification because you
>> asked the
>> >>>          question.
>> >>>
>> >>>
>> >>> Disclaimer:- This footer text is to convey that this email is
>> sent by
>> >>> one of the users of IITH. So, do not mark it as SPAM.
>> >>>
>> >> --
>> >>
>> ______________________________________________________________________
>> >> Prof. Alexander S Belyaev (<email address hidden>
>> <mailto:<email address hidden>>)
>> >> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
>> >>
>> >> School of Physics &  Astronomy, University of Southampton
>> >> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
>> >>
>> .....................................................................
>> >> Particle Physics Department, Rutherford Appleton Laboratory
>> >> Didcot,  OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
>> >>
>> .....................................................................
>> >> CERN, CH-1211 Geneva 23, Switzerland
>> >> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
>> >>
>> ______________________________________________________________________
>> >>
>> >> --
>> >> If this answers your question, please go to the following page
>> to let us
>> >> know that it is solved:
>> >>
>> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=3
>> <https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=3>
>> >>
>> >> If you still need help, you can reply to this email or go to the
>> >> following page to enter your feedback:
>> >> https://answers.launchpad.net/calchep/+question/695692
>> <https://answers.launchpad.net/calchep/+question/695692>
>> >>
>> >> You received this question notification because you asked the
>> question.
>> >>
>> > --
>> >
>> >
>> > Disclaimer:- This footer text is to convey that this email is
>> sent by one
>> > of the users of IITH. So, do not mark it as SPAM.
>> >
>>
>> --
>> ______________________________________________________________________
>> Prof. Alexander S Belyaev (<email address hidden>
>> <mailto:<email address hidden>>)
>> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
>> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
>>
>> School of Physics &  Astronomy, University of Southampton
>> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
>> .....................................................................
>> Particle Physics Department, Rutherford Appleton Laboratory
>> Didcot,  OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
>> .....................................................................
>> CERN, CH-1211 Geneva 23, Switzerland
>> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
>> ______________________________________________________________________
>>
>> --
>> If this answers your question, please go to the following page to
>> let us
>> know that it is solved:
>> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=5
>> <https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=5>
>>
>> If you still need help, you can reply to this email or go to the
>> following page to enter your feedback:
>> https://answers.launchpad.net/calchep/+question/695692
>> <https://answers.launchpad.net/calchep/+question/695692>
>>
>> You received this question notification because you asked the
>> question.
>>
>>
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Satyabrata Mahapatra (satyabrata-mahapatra) said :
#11

Respected Sir,
Thank you so much for your detailed explanation. This clarified most of my
confusions.

Thanks and Regards,
Satyabrata
=================================
Satyabrata Mahapatra
Research Scholar,
High Energy Physics Group,
Department of Physics
Indian Institute of Technology, Hyderabad
Phone: +91-7978310701, +91-7205501437
==================================

On Thu, Mar 4, 2021 at 3:05 AM Alexander Pukhov <
<email address hidden>> wrote:

> Your question #695692 on CalcHEP changed:
> https://answers.launchpad.net/calchep/+question/695692
>
> Alexander Pukhov proposed the following answer:
> Dear Satyabrata Mahapatra,
>
> It is very good that you paid attention to this moment.
>
> Let me explain to you what's going on with one example. But first of
> all I have a note about normalization factors.
>
> If we have a particle which annihilates with anti-particle, then number
> of events in space-time unit is
>
> N= vsigma*rho^2, where rho - in a number density of particles (
> not summary density of particles and antiparticles)
>
> If we have a particle which annihilates with itself then
>
> N=0.5 vsigma*rho^2
>
> In general for particle - anti-particle system we also can expect
> reactions particle,particle->SM,SM and in some models we indeed see
> such reactions.
>
> micrOMEGAs defines vSigma as
>
> vSigma = 2* Nevents /(rho_DM)^2
>
> where rho_DM includes both particles and anti-particles, and Nevents
> takes into account both particle - anti-particles and particle -
> particle annihilation if they take place.
>
> Let we have 2 particles 1 and 2 which annihilate with their
> antiparticles with the same rates vs. If mass gap is zero, then they
> have the same density rho and
>
> rho_DM =4*rho, Nevents= 2*vs*rho^2, vSigma= 2*vs*rho^2/(16*rho)^2=
> vs/8
>
> When we increase mass gap significantly the second particle disappears
> and we have
>
> rho_DM =2*rho, Nevents=vs*rho^2 , vSigma= vs/4
>
> So, it becomes twice larger, as you observe.
>
> The key point is as follows. vSigma=vs only if all pairs of
> interaction ( particle - anti-particle and particle_1 - particle_2)
> have the same vs. But in your ( it is the usual ) case many interactions
> are absent and we have vSigma= vs/8. *When one particle is avoid by
> mass shift then percent of zero interaction channels decreases and
> vSigma increases. *
>
> If you include 1,(anti) 2 ->SM,SM reaction with the same rate vs, then
> vSgma will not depend on mass gap.
>
> I hope it is clear. If not, write me once more and I'll try to find
> another words.
>
> Best
>
> Alexander Pukhov
>
>
>
>
> On 3/3/21 9:01 PM, Alexander Belyaev wrote:
> > Question #695692 on CalcHEP changed:
> > https://answers.launchpad.net/calchep/+question/695692
> >
> > Alexander Belyaev proposed the following answer:
> > Dear Satyabrata,
> >
> > I reproduce your results, but there is no mistake neither in your code
> > not in micrOMEGAs
> >
> > The point is that
> > vSigma(tm,Beps,fast) is NORMALISED on the masses of ALL DM particles,
> > see equation (1) in micrOMEGAs manual.
> > Normalisation factor is contains the SUM of K2() functions which falls
> > with M_X2 increase even if
> > the cross section of X2 X2->hh is zero. This is because X2 will still
> > contribute into the thermal equilibrium. So, wehn delta M increasing,
> > normalisation is decreasing and you have increase in sigmav -- this is
> > how it is defined.
> >
> >
> > And the same does
> > vSigmaCC(tm, newProcess("~x1,~X1 -> h, h"),1)
> > the sum of all vSigmaCC with the last argument 1 -- give you
> > vSigma(tm,Beps,fast)
> >
> > So, your code and micromegas give the correct result
> >
> > Best
> > Alexander
> >
> >
> >
> > On 03/03/2021 13:40, Dearwrote:
> >> *CAUTION:* This e-mail originated outside the University of Southampton.
> >> Respected Sir,
> >> Please find the attached code we used for obtaining the results shown
> >> in the note.
> >> I am using micrOmegas 5.0.8 for the calculation.
> >> Please let us know if you find any mistakes.
> >>
> >> Thanks & Regards,
> >> Satyabrata
> >> =================================
> >> Satyabrata Mahapatra
> >> Research Scholar,
> >> High Energy Physics Group,
> >> Department of Physics
> >> Indian Institute of Technology, Hyderabad
> >> Phone: +91-7978310701, +91-7205501437
> >> ==================================
> >>
> >>
> >> On Wed, Mar 3, 2021 at 5:41 PM Alexander Belyaev
> >> <<email address hidden>
> >> <mailto:<email address hidden>>> wrote:
> >>
> >> Your question #695692 on CalcHEP changed:
> >> https://answers.launchpad.net/calchep/+question/695692
> >> <https://answers.launchpad.net/calchep/+question/695692>
> >>
> >> Status: Open => Answered
> >>
> >> Alexander Belyaev proposed the following answer:
> >> Thanks a lot,
> >> sorry for missing it.
> >> I see now what you have got.
> >> But I can not reproduce it.
> >> Could you send me the code you have used to get these cross section
> >> behaviour?
> >> I need to see how exactly did you set parameters.
> >> Thank you,
> >> Alexander
> >>
> >>
> >> On 03/03/2021 09:50, Satyabrata Mahapatra wrote:
> >> > Question #695692 on CalcHEP changed:
> >> > https://answers.launchpad.net/calchep/+question/695692
> >> <https://answers.launchpad.net/calchep/+question/695692>
> >> >
> >> > Status: Answered => Open
> >> >
> >> > Satyabrata Mahapatra is still having a problem:
> >> > Respected Prof. Belyaev,
> >> > I had sent you a note in my first mail where we have shown the
> >> results.
> >> > I am attaching the same note with this mail. Please refer to it
> >> for details.
> >> >
> >> > The thermal averaged cross-sections are calculated using
> >> micrOmega( using
> >> > the vSigma(T,Beps,fast) routine.).
> >> >
> >> > We expect that the thermal averaged annihilation cross-section
> >> (in absence
> >> > of all co-annihilation vertices) be independent of
> >> mass-splitting and the
> >> > effective thermal averaged cross-section ( with all
> >> annihilations and
> >> > co-annihilations included) should decrease with the increase in
> >> > mass-splitting.
> >> > But we are getting the opposite results.
> >> > The same thing is happening in the model we are working on too.
> >> So to
> >> > ascertain our results we implemented this toy model.
> >> >
> >> > Please check it and let me know if I am missing anything in
> >> understanding
> >> > or is there any mistake in the procedure we are following.
> >> >
> >> > Waiting for your reply.
> >> >
> >> > Thanks and Regards,
> >> > Satyabrata
> >> >
> >> > =================================
> >> > Satyabrata Mahapatra
> >> > Research Scholar,
> >> > High Energy Physics Group,
> >> > Department of Physics
> >> > Indian Institute of Technology, Hyderabad
> >> > Phone: +91-7978310701, +91-7205501437
> >> > ==================================
> >> >
> >> >
> >> > On Wed, Mar 3, 2021 at 2:45 PM Alexander Belyaev <
> >> > <email address hidden>
> >> <mailto:<email address hidden>>> wrote:
> >> >
> >> >> Your question #695692 on CalcHEP changed:
> >> >> https://answers.launchpad.net/calchep/+question/695692
> >> <https://answers.launchpad.net/calchep/+question/695692>
> >> >>
> >> >> Status: Open => Answered
> >> >>
> >> >> Alexander Belyaev proposed the following answer:
> >> >> Dear Satyabrata,
> >> >>
> >> >> sorry for slow reply.
> >> >> In the model you have sent to me
> >> >> the cross sectio n for χ1 χ1 → h h
> >> >> does not depend on delM -- the MX1-MX2 mass split.
> >> >>
> >> >> What makes you think that thermally averaged cross-section
> >> >> depends on delM
> >> >>
> >> >> Please give me your concrete numbers and explain how did you
> >> calculate
> >> >> them.
> >> >>
> >> >> Thank you,
> >> >> Alexander
> >> >>
> >> >>
> >> >> On 03/03/2021 06:44, Satyabrata Mahapatra wrote:
> >> >>> *CAUTION:* This e-mail originated outside the University of
> >> Southampton.
> >> >>> Respected Prof. Belyaev,
> >> >>> This is just a polite reminder about a query that I had asked
> >> one week
> >> >>> ago.
> >> >>> In our model, though none of the couplings are mass-splitting
> >> >>> dependent, still we are getting results where the thermal
> averaged
> >> >>> cross-section is increasing with mass-splitting instead of
> >> decreasing.
> >> >>> Also in the absence of any co-annihilation vertex in the
> >> model, we are
> >> >>> still observing that the thermal averaged cross-section is
> >> dependent
> >> >>> on the mass-splitting.
> >> >>>
> >> >>> I had already sent you the model files to check and help us
> >> understand
> >> >>> the problem and resolving it.
> >> >>>
> >> >>> I am attaching the same in this mail again.
> >> >>>
> >> >>> Waiting for your reply.
> >> >>>
> >> >>> Thanks and Regards,
> >> >>> Satyabrata
> >> >>> =================================
> >> >>> Satyabrata Mahapatra
> >> >>> Research Scholar,
> >> >>> High Energy Physics Group,
> >> >>> Department of Physics
> >> >>> Indian Institute of Technology, Hyderabad
> >> >>> Phone: +91-7978310701, +91-7205501437
> >> >>> ==================================
> >> >>>
> >> >>>
> >> >>> On Mon, Feb 22, 2021 at 9:07 PM Satyabrata Mahapatra
> >> >>> <<email address hidden> <mailto:<email address hidden>>
> >> <mailto:<email address hidden>
> >> <mailto:<email address hidden>>>> wrote:
> >> >>>
> >> >>> Respected Prof. Belyaev,
> >> >>> Thank you so much for your prompt response.
> >> >>> Please find the attached notes regarding the toy model we
> >> have
> >> >>> implemented and the results.
> >> >>> Also I am attaching the corresponding model files.
> >> >>>
> >> >>> Kindly check it and help us resolve this issue.
> >> >>>
> >> >>> Thanks and Regards,
> >> >>> Satyabrata
> >> >>> =================================
> >> >>> Satyabrata Mahapatra
> >> >>> Research Scholar,
> >> >>> High Energy Physics Group,
> >> >>> Department of Physics
> >> >>> Indian Institute of Technology, Hyderabad
> >> >>> Phone: +91-7978310701, +91-7205501437
> >> >>> ==================================
> >> >>>
> >> >>>
> >> >>> On Mon, Feb 22, 2021 at 8:00 PM Alexander Belyaev
> >> >>> <<email address hidden>
> >> <mailto:<email address hidden>>
> >> >>> <mailto:<email address hidden>
> >> <mailto:<email address hidden>>>> wrote:
> >> >>>
> >> >>> Your question #695692 on CalcHEP changed:
> >> >>> https://answers.launchpad.net/calchep/+question/695692
> >> <https://answers.launchpad.net/calchep/+question/695692>
> >> >>>
> >> <https://answers.launchpad.net/calchep/+question/695692
> >> <https://answers.launchpad.net/calchep/+question/695692>>
> >> >>>
> >> >>> Status: Open => Answered
> >> >>>
> >> >>> Alexander Belyaev proposed the following answer:
> >> >>> Dear Satyabrata,
> >> >>>
> >> >>> we need to see your model,
> >> >>> in particular how the couplings of your model are
> >> related tot
> >> >>> he mass split.
> >> >>>
> >> >>> If some couplings in your model are proportional to
> >> the mass
> >> >>> split, then
> >> >>> the cross section will be proportional to mass-split
> >> square.
> >> >>> We need to see you model to answer your question.
> >> Description
> >> >>> in words
> >> >>> is not enough.
> >> >>>
> >> >>> Regards,
> >> >>> Alexander Belyaev
> >> >>>
> >> >>>
> >> >>> On 22/02/2021 14:15, Satyabrata Mahapatra wrote:
> >> >>> > New question #695692 on CalcHEP:
> >> >>> >
> >> https://answers.launchpad.net/calchep/+question/695692
> >> <https://answers.launchpad.net/calchep/+question/695692>
> >> >>>
> >> <https://answers.launchpad.net/calchep/+question/695692
> >> <https://answers.launchpad.net/calchep/+question/695692>>
> >> >>> >
> >> >>> > Dear Prof. Pukhov,
> >> >>> > We are working on a project and in recent few days
> >> we have
> >> >>> experimented a few things using CalcHEP and micrOmega
> >> 5.0.8.
> >> >>> > We feel that there is a bug in the micrOmega
> because of
> >> >>> which we are getting some unexpected peculiar result
> >> in our
> >> >>> work. To ascertain the results we have also
> >> implemented a Toy
> >> >>> Model in calcHEP and we are getting similar results
> >> for the
> >> >>> Toy Model too.
> >> >>> >
> >> >>> > The Details are given below:
> >> >>> >
> >> >>> > Particles in the Dark Sector:
> >> >>> > χ1 , χ2 (Z 2 odd fermions)
> >> >>> > Let the corresponding masses are M1 , M2 . Assuming
> >> M1 < M2
> >> >>> , χ1 becomes the Dark
> >> >>> > Matter candidate. Let these two particles (χ1 and
> χ2 )
> >> >>> interact with SM Higgs (h) with non-renormalizable
> >> >>> > operators.
> >> >>> >
> >> >>> > Conventionally, what one would expect is that with
> >> increase
> >> >>> in the mass-splitting (∆M ) among the dark-sector
> >> particles,
> >> >>> we expect the thermally averaged cross-section to
> >> decrease and
> >> >>> consequently the relic density to increase.
> >> >>> >
> >> >>> > But the results we are getting are opposite of it.
> >> >>> > we are puzzled about the following two points:
> >> >>> > 1) How the thermal averaged annihilation
> >> cross-section of χ1
> >> >>> (i.e. χ1 χ1 → h h) depends on
> >> >>> > the mass splitting (∆M ) or the NLSP mass (M2 )?
> >> >>> >
> >> >>> > 2) Why the thermal averaged annihilation
> >> cross-section is
> >> >>> increasing instead of decreasing with the increase of
> the
> >> >>> mass-splitting ?
> >> >>> >
> >> >>> >
> >> >>> > I have already sent an email with the results we
> >> are getting.
> >> >>> > Waiting for your reply.
> >> >>> >
> >> >>> > Thanks and Regards,
> >> >>> > Satyabrata
> >> >>> >
> >> >>> >
> >> >>>
> >> >>> --
> >> >>>
> >> >>
> >>
> ______________________________________________________________________
> >> >>> Prof. Alexander S Belyaev (<email address hidden>
> >> <mailto:<email address hidden>>
> >> >>> <mailto:<email address hidden>
> >> <mailto:<email address hidden>>>)
> >> >>> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
> >> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
> >> >>>
> >> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
> >> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>>
> >> >>>
> >> >>> School of Physics & Astronomy, University of
> Southampton
> >> >>> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44
> >> 23805 93910
> >> >>>
> >> >>
> >>
> .....................................................................
> >> >>> Particle Physics Department, Rutherford Appleton
> >> Laboratory
> >> >>> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44
> >> 12354 46733
> >> >>>
> >> >>
> >>
> .....................................................................
> >> >>> CERN, CH-1211 Geneva 23, Switzerland
> >> >>> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> >> >>>
> >> >>
> >>
> ______________________________________________________________________
> >> >>> --
> >> >>> If this answers your question, please go to the
> >> following page
> >> >>> to let us
> >> >>> know that it is solved:
> >> >>>
> >> >>
> >>
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
> >> <
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
> >
> >> >>> <
> >> >>
> >>
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
> >> <
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=0
> >
> >> >>>
> >> >>> If you still need help, you can reply to this email
> >> or go to the
> >> >>> following page to enter your feedback:
> >> >>> https://answers.launchpad.net/calchep/+question/695692
> >> <https://answers.launchpad.net/calchep/+question/695692>
> >> >>>
> >> <https://answers.launchpad.net/calchep/+question/695692
> >> <https://answers.launchpad.net/calchep/+question/695692>>
> >> >>>
> >> >>> You received this question notification because you
> >> asked the
> >> >>> question.
> >> >>>
> >> >>>
> >> >>> Disclaimer:- This footer text is to convey that this email is
> >> sent by
> >> >>> one of the users of IITH. So, do not mark it as SPAM.
> >> >>>
> >> >> --
> >> >>
> >>
> ______________________________________________________________________
> >> >> Prof. Alexander S Belyaev (<email address hidden>
> >> <mailto:<email address hidden>>)
> >> >> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
> >> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
> >> >>
> >> >> School of Physics & Astronomy, University of Southampton
> >> >> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805
> 93910
> >> >>
> >>
> .....................................................................
> >> >> Particle Physics Department, Rutherford Appleton Laboratory
> >> >> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
> >> >>
> >>
> .....................................................................
> >> >> CERN, CH-1211 Geneva 23, Switzerland
> >> >> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> >> >>
> >>
> ______________________________________________________________________
> >> >>
> >> >> --
> >> >> If this answers your question, please go to the following page
> >> to let us
> >> >> know that it is solved:
> >> >>
> >>
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=3
> >> <
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=3
> >
> >> >>
> >> >> If you still need help, you can reply to this email or go to the
> >> >> following page to enter your feedback:
> >> >> https://answers.launchpad.net/calchep/+question/695692
> >> <https://answers.launchpad.net/calchep/+question/695692>
> >> >>
> >> >> You received this question notification because you asked the
> >> question.
> >> >>
> >> > --
> >> >
> >> >
> >> > Disclaimer:- This footer text is to convey that this email is
> >> sent by one
> >> > of the users of IITH. So, do not mark it as SPAM.
> >> >
> >>
> >> --
> >>
> ______________________________________________________________________
> >> Prof. Alexander S Belyaev (<email address hidden>
> >> <mailto:<email address hidden>>)
> >> https://www.hep.phys.soton.ac.uk/content/alexander-belyaev
> >> <https://www.hep.phys.soton.ac.uk/content/alexander-belyaev>
> >>
> >> School of Physics & Astronomy, University of Southampton
> >> Office 5047, SO17 1BJ, TEL: +44 23805 98509, FAX: +44 23805 93910
> >>
> .....................................................................
> >> Particle Physics Department, Rutherford Appleton Laboratory
> >> Didcot, OX11 0QX, TEL: +44 12354 45562, FAX: +44 12354 46733
> >>
> .....................................................................
> >> CERN, CH-1211 Geneva 23, Switzerland
> >> Office 40/1-B20, Mailbox: E27910, TEL: +41 2276 71642
> >>
> ______________________________________________________________________
> >>
> >> --
> >> If this answers your question, please go to the following page to
> >> let us
> >> know that it is solved:
> >>
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=5
> >> <
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=5
> >
> >>
> >> If you still need help, you can reply to this email or go to the
> >> following page to enter your feedback:
> >> https://answers.launchpad.net/calchep/+question/695692
> >> <https://answers.launchpad.net/calchep/+question/695692>
> >>
> >> You received this question notification because you asked the
> >> question.
> >>
> >>
> >> Disclaimer:- This footer text is to convey that this email is sent by
> >> one of the users of IITH. So, do not mark it as SPAM.
> >>
>
> --
> If this answers your question, please go to the following page to let us
> know that it is solved:
> https://answers.launchpad.net/calchep/+question/695692/+confirm?answer_id=9
>
> If you still need help, you can reply to this email or go to the
> following page to enter your feedback:
> https://answers.launchpad.net/calchep/+question/695692
>
> You received this question notification because you asked the question.
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Revision history for this message
Alexander Belyaev (alexander.belyaev) said :
#12

The problem ws resolved, I am closing this questionwas resolved,
pl