Higgs Decay

Asked by Prudhvi Nikhil Bhattiprolu on 2018-06-24

Dear Madgraph Team,

I have the following two questions,

1) I am looking for a way to "generate p p > h z, (h > z z), (z > lep+ lep-)" (where I defined "lep" to be e's, mu's and ta's), but due to phase space restrictions, I am doing "generate p p > h z > z z z, (z > lep+ lep-)", but this is even decaying the z's from Higgs to also decay to leptons (which is not what I want). Can you please suggest me the right way to do this?

2) My second question is, I there a way to manually change the brancing ratios of Higgs(standard model) in madgraph? if yes, can you please suggest me some way of doing this?

Thanks much in advance!

Sincerely,
Prudhvi Bhattiprolu

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Solved by:
Olivier Mattelaer
Solved:
2018-06-25
Last query:
2018-06-25
Last reply:
2018-06-25

Hi,

> 1) I am looking for a way to "generate p p > h z, (h > z z), (z > lep+ lep-)" (where I defined "lep" to be e's, mu's and ta's), but due to phase space restrictions, I am doing "generate p p > h z > z z z, (z > lep+ lep-)", but this is even decaying the z's from Higgs to also decay to leptons (which is not what I want). Can you please suggest me the right way to do this?

I think that the easiest way is to hack the model such that you have one particle called z1 and the second z2.

> 2) My second question is, I there a way to manually change the brancing ratios of Higgs(standard model) in madgraph? if yes, can you please suggest me some way of doing this?

With the above syntax we never use the branching ratio information anywhere in the code.
Only MadSpin package is using BR for the (therefore approximate) computation.
But you can modify the BR as much as you want by modifying physical parameter (like the width of the particle) and/or by changing the coupling.

Cheers,

Olivier

> On 25 Jun 2018, at 00:13, Prudhvi Nikhil Bhattiprolu <email address hidden> wrote:
>
> New question #670439 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/670439
>
> Dear Madgraph Team,
>
> I have the following two questions,
>
> 1) I am looking for a way to "generate p p > h z, (h > z z), (z > lep+ lep-)" (where I defined "lep" to be e's, mu's and ta's), but due to phase space restrictions, I am doing "generate p p > h z > z z z, (z > lep+ lep-)", but this is even decaying the z's from Higgs to also decay to leptons (which is not what I want). Can you please suggest me the right way to do this?
>
> 2) My second question is, I there a way to manually change the brancing ratios of Higgs(standard model) in madgraph? if yes, can you please suggest me some way of doing this?
>
>
> Thanks much in advance!
>
> Sincerely,
> Prudhvi Bhattiprolu
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Thanks Olivier Mattelaer, that solved my question.