How to set any coupling to 1

Hi,

It's depend on how you want to do it.

The correct way is probably to edit your UFO model and change the expression associated to the ZWW coupling to set it to one.
Obviously you need to be careful that such statement is meaningless since some numerical factor can also be included inside the lorentz structrure. (of course do not try to edit the UFO file if it is a NLO model)

For example, the two following implementation are equivalent

C * (eta_{munu})
D*(2*eta_{munu}) = C/2 *(2*eta_{munu})

But do you want to set C or D to one?

Cheers,

Olivier

PS: I guess that the question behind this is in some sense related to reweighting. So I would suggest to read: https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/Reweight

Hi Olivier,

I set WWZp coupling to one, using following way:

1) First read the WWZp in vertices.py, from there i noted down number
corresponding that coupling i.e. GC_35.
2) Now I open couplings.py file and set the value of GC_35 to 1.

Is it correct way?

Thanks,
SK

On Wed, Oct 18, 2017 at 6:38 PM, Olivier Mattelaer <
<email address hidden>> wrote:

> Your question #659563 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/659563
>
> Status: Open => Answered
>
> Olivier Mattelaer proposed the following answer:
> Hi,
>
> It's depend on how you want to do it.
>
> The correct way is probably to edit your UFO model and change the
> expression associated to the ZWW coupling to set it to one.
> Obviously you need to be careful that such statement is meaningless since
> some numerical factor can also be included inside the lorentz structrure.
> (of course do not try to edit the UFO file if it is a NLO model)
>
> For example, the two following implementation are equivalent
>
> C * (eta_{munu})
> D*(2*eta_{munu}) = C/2 *(2*eta_{munu})
>
> But do you want to set C or D to one?
>
> Cheers,
>
> Olivier
>
> PS: I guess that the question behind this is in some sense related to
> reweighting. So I would suggest to read:
> https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/Reweight
>
> --
> 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/659563/+
> 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/mg5amcnlo/+question/659563
>
> You received this question notification because you asked the question.
>

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

Hi,

Sorry I miss your answer.
Yes this should do the job.
I would just advise you to check the definition of the lorentz structure associate to the WWZp vertex to check
if "1" is indeed the value that you want to set.

Cheers,

Olivier

Thanks.

On Fri, Nov 3, 2017 at 3:08 PM, Olivier Mattelaer <
<email address hidden>> wrote:

> Your question #659563 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/659563
>
> Olivier Mattelaer posted a new comment:
> Hi,
>
> Sorry I miss your answer.
> Yes this should do the job.
> I would just advise you to check the definition of the lorentz structure
> associate to the WWZp vertex to check
> if "1" is indeed the value that you want to set.
>
> Cheers,
>
> Olivier
>
> --
> You received this question notification because you asked the question.
>

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