bilinear interactions

Asked by Giacomo on 2020-10-16

I'd like to model the interaction of a vector meson with a photon, say. I'm doing this by implementing a bilinear term in the UFO file that involves the photon and meson. When I then try to look at a decay of the meson to an electron-positron pair mediated by the photon, I am told 'No amplitudes generated from process'. Does MadGraph accept such bilinear interactions in a UFO file, or will I have to rediagonalise everything to get rid of them?

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Solved by:
Olivier Mattelaer
Solved:
2020-10-16
Last query:
2020-10-16
Last reply:
2020-10-16

Is it a 2 point interaction?

> On 16 Oct 2020, at 19:00, Giacomo <email address hidden> wrote:
>
> New question #693491 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/693491
>
> I'd like to model the interaction of a vector meson with a photon, say. I'm doing this by implementing a bilinear term in the UFO file that involves the photon and meson. When I then try to look at a decay of the meson to an electron-positron pair through mediated by the photon, I am told 'No amplitudes generated from process'. Does MadGraph accept such bilinear interactions in a UFO file, or will I have to rediagonalise everything to get rid of them?
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Giacomo (gmarocco) said : #2

Yes it is.

Then indeed 2 point interaction are not supported in mG5aMC.

Giacomo (gmarocco) said : #4

Ok, thank you Olivier.

Giacomo (gmarocco) said : #5

Thanks Olivier Mattelaer, that solved my question.