MadGraph5_aMC@NLO

Missing diagrams in inclusive generation

Asked by Peter Winslow

Hi,

I've implemented a NP model that includes a new singlet scalar that mixes with the Higgs. I also implemented the effective scalar couplings to gluons and photons. I'm interested in a 4 tau final state so I generate p p > ta+ ta- ta+ ta- and, when I display the diagrams there are some crucial diagrams that are missing. For instance, there are diagrams where one of the scalars appears in the s-channel via glue-glue fusion, decays to two photons, and then both photons split to ta+ ta-. However, the diagrams where the photons are replaced with Z's are missing. Also, one of the scalars is missing completely from all diagrams. To investigate, I generate the same process, but now asking specifically for the Z's or the missing scalar in the intermediate state and, at this point, they both show up no problem. For some reason, they're just missing when I ask for all possible diagrams. Do you know of any reason as to why this would happen?

Best,
Peter

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Olivier Mattelaer (olivier-mattelaer) said : 		#1

Hi Peter,

You will be interested in this FAQ:
https://answers.launchpad.net/mg5amcnlo/+faq/1942

Cheers,

Olivier

On 06 Mar 2015, at 23:51, Peter Winslow <email address hidden> wrote:

> New question #263325 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/263325
>
> Hi,
>
> I've implemented a NP model that includes a new singlet scalar that mixes with the Higgs. I also implemented the effective scalar couplings to gluons and photons. I'm interested in a 4 tau final state so I generate p p > ta+ ta- ta+ ta- and, when I display the diagrams there are some crucial diagrams that are missing. For instance, there are diagrams where one of the scalars appears in the s-channel via glue-glue fusion, decays to two photons, and then both photons split to ta+ ta-. However, the diagrams where the photons are replaced with Z's are missing. Also, one of the scalars is missing completely from all diagrams. To investigate, I generate the same process, but now asking specifically for the Z's or the missing scalar in the intermediate state and, at this point, they both show up no problem. For some reason, they're just missing when I ask for all possible diagrams. Do you know of any reason as to why this would happen?
>
> Best,
> Peter
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

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