WWG couplings

Asked by Murat on 2020-12-20

Hi,

I wanted to contribution of the only anomalous WWG coupling contributes to aa>ww process in EWdim6 model.

In madgraph, after importing the EWdim6 model, I used the command
generate a a > w+ w- /h. This process has 5 diagrams.

My first question is this: the a a > w+ w- /h process has 3 diagrams. But there are 5 diagrams here.
What is the reason of this? How can I get the correct number of diagrams?.

My second question is that I just want to examine the only anomalous WWG coupling, not WWGG. But in the process, WWGG quatric coupling is also coming, how can I handle this?

Regards,
Murat

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
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Solved by:
Murat
Solved:
2020-12-20
Last query:
2020-12-20
Last reply:
2020-12-20

The default rule of the model to keep relevant contribution leads to weird effect for your process, the solution is to specify the order that you want
generate a a > w+ w- /h NP=0
-> generate only the SM contribution (3 diagram)
generate a a > w+ w- /h NP<=2
-> generate only the SM contribution (3 diagram) + the BSM contribution (5 diagram)

> My second question is that I just want to examine the only anomalous WWG coupling, not WWGG. But in the process, WWGG quatric coupling is also coming, how can I handle this?

In the EFT approach those two vertice are generated by a single one EFT operator.
Not doing so is likely to break gauge and lorentz invariance (and obviously unitarity). So I would strongly recommend to not do that. If you want to do it, the easiest solution is to modify the UFO model to remove that interaction from the model.

Cheers,

Olivier

Murat (ribella) said : #2

Thanks Olivier.