cross section is very small in MG5

What are the real value for the total width?
If you do not put the correct one and put much larger one then your cross-section will be much smaller indeed.

Cheers,

Olivier

> On 4 Mar 2018, at 12:38, Deepanjali Goswami <email address hidden> wrote:
>
> New question #665193 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/665193
>
> Dear experts,
>
> I am trying to generate a process in MG5 for model (TypeIIseesaw + Inert Higgs Doublet) : p p > D+ D0, (D+ > w+ D0, D0 > H0 H0).
> Mass for all scalars are set as :M_D+ = 316 GeV, M_D0 = 200 GeV, M_H0 = 65 GeV.
> where D+ and D0 are scalars in type II seesaw model and H0 is the lightest neutral scalar in Inert Higgs doublet model.
>
> When I do not define the decaying products , the production cross section for p p > D+ D0 is ~ 0.01698 pb.
>
> If I allow the decaying products like
> generate p p > D+ D0, (D+ > w+ D0, D0 > H0 H0, w+ > l+ vl)
>
> then cross section becomes very small which is ~ 1.263e-24 +- 3.275e-27 pb and it is very different than the one I expect
> Total cross-section x BR(D+ > w+ D0) x BR(D0 > H0 H0) = 0.01698*0.43*0.845 pb = 0.0062 pb.
>
> I have tried varying the bwcutoff by giving a value starting from a smaller to larger like 10K with the cut_decays to false.
>
> I have followed the thread https://answers.launchpad.net/mg5amcnlo/+question/239366 thinking its the same issue but I could not resolve my issue.
> I tried changing the width of D0 from smaller (0.01 GeV) to large value(10^2 GeV) to check it but it seems problem remains same.
>
>
> May I ask you for a suggestions/ways to solve my problem such that I get expected cross-section .
>
> Many thanks and regards,
> Deepanjali
>
>
>
>
>
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Olivier,

Thanks for your quick reply.

I tried putting real values of Total Width for D+ and D0 also, same small cross section for the below mentioned values.
These are : Total Width (D+) = 3.89 GeV, TotalWidth (D0) = 0.76 GeV.

I hope this information shall help you.

Thanks and regards,
Deepanjali

Hi,

How did you compute such value? did you use "Auto" or an external calculator?
With such value I do not see why you should have such behavior.
Cab you compute the cross-section for

> generate p p > D+ D0, D+ > w+ D0

Such that we can see if the problem is with the D+ decay and/or with the D0 decay.

Cheers,

Olivier

> On 4 Mar 2018, at 17:01, Deepanjali Goswami <email address hidden> wrote:
>
> Question #665193 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/665193
>
> Deepanjali Goswami posted a new comment:
> Hi Olivier,
>
> Thanks for your quick reply.
>
> I tried putting real values of Total Width for D+ and D0 also, same small cross section for the below mentioned values.
> These are : Total Width (D+) = 3.89 GeV, TotalWidth (D0) = 0.76 GeV.
>
> I hope this information shall help you.
>
> Thanks and regards,
> Deepanjali
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi,

I computed the total decay width by putting "Auto", no external calculator.

The cross section by MG5 for

generate p p > D+ D0, D+ > w+ D0

and the cross section ~ 0.006619 +- 2.066e-05 pb
 which is expected by production cross scetion x BR ~ 0.0073 pb .

Thanks and regards,
Deepanjali

Ok so the problem seems to be in D0 > H0H0

can you send
1) the details of the D0 width computation
2) compute with madevent D0 > all all such that we can compare with 1
3) compute
generate D+ > w+ D0, D0 > H0 H0
to see if this process is also suppress. Maybe they are a suppression due to some lorentz structure incompatibility between both decay.

Cheers,

Olivier

PS: I'm not working for the physics department on Monday and Tuesday, so my next reply will be on wednesday.
If you still not have found the issue by that time, the best is likely that you send me your model and the script to setup
your cards such that I can try to reproduce your problem.

> On 5 Mar 2018, at 08:37, Deepanjali Goswami <email address hidden> wrote:
>
> Question #665193 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/665193
>
> Deepanjali Goswami posted a new comment:
> Hi,
>
> I computed the total decay width by putting "Auto", no external
> calculator.
>
> The cross section by MG5 for
>
> generate p p > D+ D0, D+ > w+ D0
>
> and the cross section ~ 0.006619 +- 2.066e-05 pb
> which is expected by production cross scetion x BR ~ 0.0073 pb .
>
> Thanks and regards,
> Deepanjali
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Olivier,

Thanks a lot for your reply.

Yes, the problem is with the decay channel D0 > H0H0.
I found the cross-scetion by MG5 for
generate p p > D+ D0, (D+ > w+ D0) ~ 0.006619 +- 2.066e-05 pb , and

generate p p > D+ D0, (D0 > H0 H0) ~ 2.82e-24 +- 4.4e-27 pb.

Coming to your investigations:
1) the D0 decay width computation, Width(D0 > H0H0) = mu2^2*sqrt(1- 4*mH0^2/mD0^2)/ (8pi*mD0) = 0.7559 GeV which is exactly same as MG5 computation.
where mu2 is the mass dimension 1 coupling , which is taken as 100 GeV for our calculation.
mH0 = 65 GeV, mD0 = 200 GeV.

2) Total Width D0 > all all ~ 0.8939 GeV
3) generate D+ > w+ D0, D0 > H0 H0 ~ 2.789e-22 +- 1.01e-25 GeV

Problem is not yet solved and I can forward you the model file to resolve the issue.

Many thanks and regards,
Deepanjali

yes please send me the model and i will look tommorow (at earliest)

Olivier

> On 6 Mar 2018, at 10:16, Deepanjali Goswami <email address hidden> wrote:
>
> Question #665193 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/665193
>
> Deepanjali Goswami posted a new comment:
> Hi Olivier,
>
> Thanks a lot for your reply.
>
> Yes, the problem is with the decay channel D0 > H0H0.
> I found the cross-scetion by MG5 for
> generate p p > D+ D0, (D+ > w+ D0) ~ 0.006619 +- 2.066e-05 pb , and
>
> generate p p > D+ D0, (D0 > H0 H0) ~ 2.82e-24 +- 4.4e-27 pb.
>
>
> Coming to your investigations:
> 1) the D0 decay width computation, Width(D0 > H0H0) = mu2^2*sqrt(1- 4*mH0^2/mD0^2)/ (8pi*mD0) = 0.7559 GeV which is exactly same as MG5 computation.
> where mu2 is the mass dimension 1 coupling , which is taken as 100 GeV for our calculation.
> mH0 = 65 GeV, mD0 = 200 GeV.
>
>
> 2) Total Width D0 > all all ~ 0.8939 GeV
> 3) generate D+ > w+ D0, D0 > H0 H0 ~ 2.789e-22 +- 1.01e-25 GeV
>
> Problem is not yet solved and I can forward you the model file to
> resolve the issue.
>
> Many thanks and regards,
> Deepanjali
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Olivier,

I have sent the model-UFO file along with this email.
Kindly find it.

Thanks and regards,
Deepanjali

> Your question #665193 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/665193
>
> Olivier Mattelaer proposed the following answer:
> yes please send me the model and i will look tommorow (at earliest)
>
> Olivier
>
>> On 6 Mar 2018, at 10:16, Deepanjali Goswami
>> <email address hidden> wrote:
>>
>> Question #665193 on MadGraph5_aMC@NLO changed:
>> https://answers.launchpad.net/mg5amcnlo/+question/665193
>>
>> Deepanjali Goswami posted a new comment:
>> Hi Olivier,
>>
>> Thanks a lot for your reply.
>>
>> Yes, the problem is with the decay channel D0 > H0H0.
>> I found the cross-scetion by MG5 for
>> generate p p > D+ D0, (D+ > w+ D0) ~ 0.006619 +- 2.066e-05 pb , and
>>
>> generate p p > D+ D0, (D0 > H0 H0) ~ 2.82e-24 +- 4.4e-27 pb.
>>
>>
>> Coming to your investigations:
>> 1) the D0 decay width computation, Width(D0 > H0H0) = mu2^2*sqrt(1-
>> 4*mH0^2/mD0^2)/ (8pi*mD0) = 0.7559 GeV which is exactly same as MG5
>> computation.
>> where mu2 is the mass dimension 1 coupling , which is taken as 100 GeV
>> for our calculation.
>> mH0 = 65 GeV, mD0 = 200 GeV.
>>
>>
>> 2) Total Width D0 > all all ~ 0.8939 GeV
>> 3) generate D+ > w+ D0, D0 > H0 H0 ~ 2.789e-22 +- 1.01e-25 GeV
>>
>> Problem is not yet solved and I can forward you the model file to
>> resolve the issue.
>>
>> Many thanks and regards,
>> Deepanjali
>>
>> --
>> You received this question notification because you are an answer
>> contact for MadGraph5_aMC@NLO.
>
> --
> If this answers your question, please go to the following page to let us
> know that it is solved:
> https://answers.launchpad.net/mg5amcnlo/+question/665193/+confirm?answer_id=6
>
> 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/mg5amcnlo/+question/665193
>
> You received this question notification because you asked the question.
>

Hi,

attachment does not go trough launchpad for question.
please send it directly to me, or create a bug report

Cheers,

Olivier

> On 6 Mar 2018, at 13:22, Deepanjali Goswami <email address hidden> wrote:
>
> Question #665193 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/665193
>
> Status: Answered => Open
>
> Deepanjali Goswami is still having a problem:
>
> Hi Olivier,
>
> I have sent the model-UFO file along with this email.
> Kindly find it.
>
> Thanks and regards,
> Deepanjali
>
>
>> Your question #665193 on MadGraph5_aMC@NLO changed:
>> https://answers.launchpad.net/mg5amcnlo/+question/665193
>>
>> Olivier Mattelaer proposed the following answer:
>> yes please send me the model and i will look tommorow (at earliest)
>>
>> Olivier
>>
>>> On 6 Mar 2018, at 10:16, Deepanjali Goswami
>>> <email address hidden> wrote:
>>>
>>> Question #665193 on MadGraph5_aMC@NLO changed:
>>> https://answers.launchpad.net/mg5amcnlo/+question/665193
>>>
>>> Deepanjali Goswami posted a new comment:
>>> Hi Olivier,
>>>
>>> Thanks a lot for your reply.
>>>
>>> Yes, the problem is with the decay channel D0 > H0H0.
>>> I found the cross-scetion by MG5 for
>>> generate p p > D+ D0, (D+ > w+ D0) ~ 0.006619 +- 2.066e-05 pb , and
>>>
>>> generate p p > D+ D0, (D0 > H0 H0) ~ 2.82e-24 +- 4.4e-27 pb.
>>>
>>>
>>> Coming to your investigations:
>>> 1) the D0 decay width computation, Width(D0 > H0H0) = mu2^2*sqrt(1-
>>> 4*mH0^2/mD0^2)/ (8pi*mD0) = 0.7559 GeV which is exactly same as MG5
>>> computation.
>>> where mu2 is the mass dimension 1 coupling , which is taken as 100 GeV
>>> for our calculation.
>>> mH0 = 65 GeV, mD0 = 200 GeV.
>>>
>>>
>>> 2) Total Width D0 > all all ~ 0.8939 GeV
>>> 3) generate D+ > w+ D0, D0 > H0 H0 ~ 2.789e-22 +- 1.01e-25 GeV
>>>
>>> Problem is not yet solved and I can forward you the model file to
>>> resolve the issue.
>>>
>>> Many thanks and regards,
>>> Deepanjali
>>>
>>> --
>>> You received this question notification because you are an answer
>>> contact for MadGraph5_aMC@NLO.
>>
>> --
>> If this answers your question, please go to the following page to let us
>> know that it is solved:
>> https://answers.launchpad.net/mg5amcnlo/+question/665193/+confirm?answer_id=6
>>
>> 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/mg5amcnlo/+question/665193
>>
>> You received this question notification because you asked the question.
>>
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Olivier,

I have sent the model file by email to you.

Thanks and regards,
Deepanjali

Hi,

When did you have done it?
What was the subject of that email?
I do not have receive such email?

Cheers,

Olivier

> On 6 Mar 2018, at 13:47, Deepanjali Goswami <email address hidden> wrote:
>
> Question #665193 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/665193
>
> Deepanjali Goswami posted a new comment:
> Hi Olivier,
>
> I have sent the model file by email to you.
>
> Thanks and regards,
> Deepanjali
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi,

May I ask your email id to send the model file. I sent it via this
launchpad so you did not receive it.

Thanks and regards,
Deepanjali

> Your question #665193 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/665193
>
> Status: Open => Answered
>
> Olivier Mattelaer proposed the following answer:
> Hi,
>
> attachment does not go trough launchpad for question.
> please send it directly to me, or create a bug report
>
> Cheers,
>
> Olivier
>
>> On 6 Mar 2018, at 13:22, Deepanjali Goswami
>> <email address hidden> wrote:
>>
>> Question #665193 on MadGraph5_aMC@NLO changed:
>> https://answers.launchpad.net/mg5amcnlo/+question/665193
>>
>> Status: Answered => Open
>>
>> Deepanjali Goswami is still having a problem:
>>
>> Hi Olivier,
>>
>> I have sent the model-UFO file along with this email.
>> Kindly find it.
>>
>> Thanks and regards,
>> Deepanjali
>>
>>
>>> Your question #665193 on MadGraph5_aMC@NLO changed:
>>> https://answers.launchpad.net/mg5amcnlo/+question/665193
>>>
>>> Olivier Mattelaer proposed the following answer:
>>> yes please send me the model and i will look tommorow (at earliest)
>>>
>>> Olivier
>>>
>>>> On 6 Mar 2018, at 10:16, Deepanjali Goswami
>>>> <email address hidden> wrote:
>>>>
>>>> Question #665193 on MadGraph5_aMC@NLO changed:
>>>> https://answers.launchpad.net/mg5amcnlo/+question/665193
>>>>
>>>> Deepanjali Goswami posted a new comment:
>>>> Hi Olivier,
>>>>
>>>> Thanks a lot for your reply.
>>>>
>>>> Yes, the problem is with the decay channel D0 > H0H0.
>>>> I found the cross-scetion by MG5 for
>>>> generate p p > D+ D0, (D+ > w+ D0) ~ 0.006619 +- 2.066e-05 pb , and
>>>>
>>>> generate p p > D+ D0, (D0 > H0 H0) ~ 2.82e-24 +- 4.4e-27 pb.
>>>>
>>>>
>>>> Coming to your investigations:
>>>> 1) the D0 decay width computation, Width(D0 > H0H0) = mu2^2*sqrt(1-
>>>> 4*mH0^2/mD0^2)/ (8pi*mD0) = 0.7559 GeV which is exactly same as MG5
>>>> computation.
>>>> where mu2 is the mass dimension 1 coupling , which is taken as 100 GeV
>>>> for our calculation.
>>>> mH0 = 65 GeV, mD0 = 200 GeV.
>>>>
>>>>
>>>> 2) Total Width D0 > all all ~ 0.8939 GeV
>>>> 3) generate D+ > w+ D0, D0 > H0 H0 ~ 2.789e-22 +- 1.01e-25 GeV
>>>>
>>>> Problem is not yet solved and I can forward you the model file to
>>>> resolve the issue.
>>>>
>>>> Many thanks and regards,
>>>> Deepanjali
>>>>
>>>> --
>>>> You received this question notification because you are an answer
>>>> contact for MadGraph5_aMC@NLO.
>>>
>>> --
>>> If this answers your question, please go to the following page to let
>>> us
>>> know that it is solved:
>>> https://answers.launchpad.net/mg5amcnlo/+question/665193/+confirm?answer_id=6
>>>
>>> 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/mg5amcnlo/+question/665193
>>>
>>> You received this question notification because you asked the question.
>>>
>>
>> --
>> You received this question notification because you are an answer
>> contact for MadGraph5_aMC@NLO.
>
> --
> If this answers your question, please go to the following page to let us
> know that it is solved:
> https://answers.launchpad.net/mg5amcnlo/+question/665193/+confirm?answer_id=8
>
> 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/mg5amcnlo/+question/665193
>
> You received this question notification because you asked the question.
>

hi,

It is actually in my profile. But here it is:
<email address hidden><mailto:<email address hidden>>

Cheers,

Olivier

On 6 Mar 2018, at 18:27, Deepanjali Goswami <<email address hidden><mailto:<email address hidden>>> wrote:

Question #665193 on MadGraph5_aMC@NLO changed:
https://answers.launchpad.net/mg5amcnlo/+question/665193

   Status: Answered => Open

Deepanjali Goswami is still having a problem:
Hi,

May I ask your email id to send the model file. I sent it via this
launchpad so you did not receive it.

Thanks and regards,
Deepanjali

Your question #665193 on MadGraph5_aMC@NLO changed:
https://answers.launchpad.net/mg5amcnlo/+question/665193

   Status: Open => Answered

Olivier Mattelaer proposed the following answer:
Hi,

attachment does not go trough launchpad for question.
please send it directly to me, or create a bug report

Cheers,

Olivier

On 6 Mar 2018, at 13:22, Deepanjali Goswami
<email address hidden> wrote:

Question #665193 on MadGraph5_aMC@NLO changed:
https://answers.launchpad.net/mg5amcnlo/+question/665193

  Status: Answered => Open

Deepanjali Goswami is still having a problem:

Hi Olivier,

I have sent the model-UFO file along with this email.
Kindly find it.

Thanks and regards,
Deepanjali

Your question #665193 on MadGraph5_aMC@NLO changed:
https://answers.launchpad.net/mg5amcnlo/+question/665193

Olivier Mattelaer proposed the following answer:
yes please send me the model and i will look tommorow (at earliest)

Olivier

On 6 Mar 2018, at 10:16, Deepanjali Goswami
<email address hidden> wrote:

Question #665193 on MadGraph5_aMC@NLO changed:
https://answers.launchpad.net/mg5amcnlo/+question/665193

Deepanjali Goswami posted a new comment:
Hi Olivier,

Thanks a lot for your reply.

Yes, the problem is with the decay channel D0 > H0H0.
I found the cross-scetion by MG5 for
generate p p > D+ D0, (D+ > w+ D0) ~ 0.006619 +- 2.066e-05 pb , and

generate p p > D+ D0, (D0 > H0 H0) ~ 2.82e-24 +- 4.4e-27 pb.

Coming to your investigations:
1) the D0 decay width computation, Width(D0 > H0H0) = mu2^2*sqrt(1-
4*mH0^2/mD0^2)/ (8pi*mD0) = 0.7559 GeV which is exactly same as MG5
computation.
where mu2 is the mass dimension 1 coupling , which is taken as 100 GeV
for our calculation.
mH0 = 65 GeV, mD0 = 200 GeV.

2) Total Width D0 > all all ~ 0.8939 GeV
3) generate D+ > w+ D0, D0 > H0 H0 ~ 2.789e-22 +- 1.01e-25 GeV

Problem is not yet solved and I can forward you the model file to
resolve the issue.

Many thanks and regards,
Deepanjali

--
You received this question notification because you are an answer
contact for MadGraph5_aMC@NLO.

--
If this answers your question, please go to the following page to let
us
know that it is solved:
https://answers.launchpad.net/mg5amcnlo/+question/665193/+confirm?answer_id=6

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/mg5amcnlo/+question/665193

You received this question notification because you asked the question.

--
You received this question notification because you are an answer
contact for MadGraph5_aMC@NLO.

--
If this answers your question, please go to the following page to let us
know that it is solved:
https://answers.launchpad.net/mg5amcnlo/+question/665193/+confirm?answer_id=8

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/mg5amcnlo/+question/665193

You received this question notification because you asked the question.

--
You received this question notification because you are an answer
contact for MadGraph5_aMC@NLO.

Hi,

I have run the following script:
import model TypeII_IDM_37_diag_UFO --modelname
generate D0 > ~H0 ~H0
output
launch
set mmd0 200
set mmh0 65
set width all Auto

Did you change any other parameter compare to the default spectrum?

Because for the above run, I do not reproduce your result:

In this case the ~H0 is stable:
#
# PDG Width
DECAY 35 0.000000e+00

But the D0 particle does not decay at all in ~H0 (and the width is very small)
#
# PDG Width
DECAY 150 6.673366e-14
# BR NDA ID1 ID2 ...
   7.163701e-01 3 -5 5 25 # 4.78059991117e-14
   1.441289e-01 2 23 23 # 9.6182481167e-15
   1.033558e-01 2 -24 24 # 6.89730922576e-15
   3.614518e-02 3 -15 15 25 # 2.41209988389e-15

This is normal since the two couplings associate to the D0 > ~H0 ~H0 are both vanishing:
        GC_83 = 0.00000E+00 0.00000E+00
       GC_189 = -0.00000E+00 -0.00000E+00

        GC_83 = mdl_complexi*mdl_mu2*mdl_sqrt__2
        GC_189 = -(mdl_complexi*mdl_lam6bar*mdl_vtt) - mdl_complexi*mdl_lam7bar*mdl_vtt

Please provide me information on how to edit the benchmark point such that we can run on the same benchmark.

Cheers,

Olivier

Hi Olivier,

Other parameters also need to change.

I am sending you the parameter card to your email where we have set the benchmark.

Thanks and regards,
Deepanjali

Hi,

This seems to be related to some inconsistency in the coupling order associated with your model.
Since you do not specify any coupling order for your process, we use the default of MG, which is, in this case, the leading contribution.
But in your case, the model wrongly claim that the leading contribution as the subleading.

One solution is to force MG5aMC to consider all order by asking:
generate p p > D+ D0, (D0 > H0 H0 QED<=3)

Cheers,

Olivier

Hi Olivier,

Thank you so much for solving the issue. I have checked with generate p p > D+ D0, (D0 > H0 H0 QED<=3). Its alright now .

We will revisit the model file and will contact you for further details.

Many thanks and regards,
Deepanjali

Thanks Olivier Mattelaer, that solved my question.

Hi Olivier ,

I have a query in the same model (Type II seesaw model + Inert Doublet model ). When I generate process in MG5_aMC, p p > D++ D-, (D++ > H+ H+, H+ > j j H0, H+ > l+ vl H0), ( D- > H- H0, H- > l- vl H0)., cross section comes out to be very small (~ 10^-45 pb) , which should be around few fb analytically. Can you plz point out my mistake.

Many thanks,
Deepanjali

This question was expired because it remained in the 'Open' state without activity for the last 15 days.