MadGraph5_aMC@NLO

The process stops after a long time

Asked by Shirin

Dear Expert,

I am trying to generate the following sample by importing
SMEFTatNLO model.
I follow the commands below
define p = p b b~
define j = j b b~
import model SMEFTatNLO
generate p p > h w+ w- [QCD]
I don't receive any errors, but this process stops after a long time and no longer goes forward. Could you please guide me?

Thanks a lot.

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Olivier Mattelaer (olivier-mattelaer) said : 		#1

That process is not suppose to work since you are doing 5 flavor computation.
Indeed in this case the real diagram contains a resonant amplitude (the top) and that makes the physics to not compute the "correct" NLO result for that process (since the top will blow up the NLO cross-section).

MG5aMC alone is not able to handle such process but if you are using the MadSTR plugin that you can specify various treatment on how to remove the resonant contribution of the top quark and make the code to converge (and to return physical result).

Cheers,

Olivier

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Shirin (shirinphy) said : 		#2

  Thanks a lot for your response
I did the following command for something you said
./bin/mg5_aMC --mode=MadSTR
and I retried with the same before commands. Now I have the following error, how can I solve it?

With MadSTR, the launch command must not be executed from the MG5_aMC shell.
        Rather, the event generation / cross-section computation should be launched from within the process directory.

Thanks again.

Revision history for this message
Olivier Mattelaer (olivier-mattelaer) said : 		#3

what it means is that you can not use the "launch" command for MG5aMC
but need to do

cd PROCESS_DIRECTORY
./bin/generate_events

instead.

Cheers,

Olivier
> On 29 Feb 2024, at 18:10, Shirin <email address hidden> wrote:
>
> Question #709452 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/709452
>
> Status: Answered => Open
>
> Shirin is still having a problem:
> Thanks a lot for your response
> I did the following command for something you said
> ./bin/mg5_aMC --mode=MadSTR
> and I retried with the same before commands. Now I have the following error, how can I solve it?
>
> With MadSTR, the launch command must not be executed from the MG5_aMC shell.
> Rather, the event generation / cross-section computation should be launched from within the process directory.
>
> Thanks again.
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

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