Syntax for Z-boson and photon fusion

Without knowing the model, I can not give such answer.
In general:
generate e+e- > e+e- ALP
should be the correct syntax.
After that if this produces too many diagrams and you want to remove some you can look at the associated FAQ.

Cheers,

Olivier

Dear Oliver,

Thanks for your reply.
My Model is the general model for ALP(a).

If the command "*generate e+ e- > e+ e- a"* produces the following
diagrams, *Then what is the syntax of generating the Middle one*? the
photon Z boson fusion.

1) The first diagram i produced using *generate e+ e- > e+ e- a / \gamma,
e+ e-, h*
2) The third one i produced using *generate e+ e- > e+ e- a / z, e+ e-,
h,*
*How can I explicitly produce the middle one?*

[image: MO.png]

The model is given below,
[image: model.png]

Best regards
Ouseph

On Mon, Nov 21, 2022 at 8:50 PM Olivier Mattelaer <
<email address hidden>> wrote:

> Your question #703889 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/703889
>
> Status: Open => Answered
>
> Olivier Mattelaer proposed the following answer:
> Without knowing the model, I can not give such answer.
> In general:
> generate e+e- > e+e- ALP
> should be the correct syntax.
> After that if this produces too many diagrams and you want to remove some
> you can look at the associated FAQ.
>
> Cheers,
>
> Olivier
>
> --
> If this answers your question, please go to the following page to let us
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>
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Hi,

Looks like they are formatting issue with your answer, I guess that you reply via your email and that you are using rich extension/html format and image that are not accepted for the web page.

Cheers,

Olivier

Dear Oliver
Sorry for the unsupporting format,

ax=ALP
a=Photon=\gamma

For example, I could generate ALP (ax) from the

1) \gamma-\gamma fusion using
     generate e+ e- > e+ e- ax / z e+ e- h

2) Z-Z fusion using
     generate e+ e- > e+ e- ax / a e+ e- h

Then How can I generate ALP from the
3) Z-\gamma fusion ?

I am using The UFO model file for the linear EFT of ALP (https://feynrules.irmp.ucl.ac.be/wiki/ALPsEFT).

Best
Ouseph

Olivier Mattelaer suggests this article as an answer to your question:
FAQ #3322: “How to select of subset of diagram for LO computation?”.

You need to use a diagram selection algorithm here.
We do not have syntax for such type of diagram since this typically break gauge invariance and is therefore meaningless.

Cheers,

Olivier