Off shell particle production

You can use your first syntax and set the mass of the Z prime much higher than sqrts...

Cheers,

Olivier
> On 14 Apr 2019, at 13:09, nilanjana <email address hidden> wrote:
>
> New question #680245 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/680245
>
> Hi,
>
> I am trying to generate g s > b ta+ ta-, where a Z' is involved. I can also write g s > b Z', Z' > ta+ ta-. I can generate
> both process successfully in my model file. But how can I make the cross section independent of the Z' mass? or in other
> words, how can I make this Z' offshell? I am trying to check the cross section in four Fermi limit.
>
> I have tried putting $ Z and also using a higher value of bwcutoff, but none of them worked.
>
> I really appreciate your help.
>
> Thanks,
> Nilanjana
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Thanks Olivier for your prompt reply.

Yes I have already tried increasing the mass of Z' much higher than 13 TeV, I am simulating 13 TeV LHC.
But the cross section is still decreasing with increasing Z' mass, the cross section for Z'= 70 TeV is smaller by
a factor of 10 than the cross section at Z'=30 TeV. So it is not working.

Thanks again!

Nilanjana
.

I think that this is correct. The mass of the z prime is part of the coupling of the associated fermi theory

Don’t you agree? Or do I miss the reason why it should not depend of the mass

Cheers

Olivier

Get Outlook for iOS<https://aka.ms/o0ukef>

________________________________
From: <email address hidden> on behalf of nilanjana <email address hidden>
Sent: Sunday, April 14, 2019 3:37 PM
To: Olivier Mattelaer
Subject: Re: [Question #680245]: Off shell particle production

Question #680245 on MadGraph5_aMC@NLO changed:
https://answers.launchpad.net/mg5amcnlo/+question/680245

Status: Answered => Open

nilanjana is still having a problem:
Thanks Olivier for your prompt reply.

Yes I have already tried increasing the mass of Z' much higher than 13 TeV, I am simulating 13 TeV LHC.
But the cross section is still decreasing with increasing Z' mass, the cross section for Z'= 70 TeV is smaller by
a factor of 10 than the cross section at Z'=30 TeV. So it is not working.

Thanks again!

Nilanjana
.

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

Thanks Olivier for your reply. Yes, The couplings also need to be scaled
with mZ'.

Nilanjana

On Sun, Apr 14, 2019 at 7:38 PM Olivier Mattelaer <
<email address hidden>> wrote:

> Your question #680245 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/680245
>
> Status: Open => Answered
>
> Olivier Mattelaer proposed the following answer:
> I think that this is correct. The mass of the z prime is part of the
> coupling of the associated fermi theory
>
> Don’t you agree? Or do I miss the reason why it should not depend of the
> mass
>
> Cheers
>
> Olivier
>
> Get Outlook for iOS<https://aka.ms/o0ukef>
>
> ________________________________
> From: <email address hidden> on behalf of nilanjana <
> <email address hidden>>
> Sent: Sunday, April 14, 2019 3:37 PM
> To: Olivier Mattelaer
> Subject: Re: [Question #680245]: Off shell particle production
>
> Question #680245 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/680245
>
> Status: Answered => Open
>
> nilanjana is still having a problem:
> Thanks Olivier for your prompt reply.
>
> Yes I have already tried increasing the mass of Z' much higher than 13
> TeV, I am simulating 13 TeV LHC.
> But the cross section is still decreasing with increasing Z' mass, the
> cross section for Z'= 70 TeV is smaller by
> a factor of 10 than the cross section at Z'=30 TeV. So it is not working.
>
> Thanks again!
>
> Nilanjana
> .
>
> --
> 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/680245/+confirm?answer_id=2
>
> 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/680245
>
> You received this question notification because you asked the question.
>

--
Thanks,

Dr. Nilanjana Kumar

Post Doctoral Fellow
Theoretical Physics division
Institute of Mathematical Sciences,
Room no NIB-106,
Taramani, Chennai 600 113
Tamil Nadu, India.

Should not it be scaled vy mZ'^2 in order to have a constant cross-section?

Cheers,

Olivier

Yes I meant that actually. Thanks again for your help.

On Mon 15 Apr, 2019, 12:57 AM Olivier Mattelaer, <
<email address hidden>> wrote:

> Your question #680245 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/680245
>
> Status: Open => Answered
>
> Olivier Mattelaer proposed the following answer:
> Should not it be scaled vy mZ'^2 in order to have a constant cross-
> section?
>
> Cheers,
>
> Olivier
>
> --
> 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/680245/+confirm?answer_id=4
>
> 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/680245
>
> You received this question notification because you asked the question.
>

Hi,

So do you still need help?
Or can I consider this thread as resolved?

Cheers,

Olivier

Yes my question is solved. Thanks again for your help.

On Mon 15 Apr, 2019, 1:12 AM Olivier Mattelaer, <
<email address hidden>> wrote:

> Your question #680245 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/680245
>
> Status: Open => Answered
>
> Olivier Mattelaer proposed the following answer:
> Hi,
>
> So do you still need help?
> Or can I consider this thread as resolved?
>
> Cheers,
>
> Olivier
>
> --
> 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/680245/+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/680245
>
> You received this question notification because you asked the question.
>