How to use Pythia8 manually?

Asked by Winston on 2020-09-02

Hi experts,
 I have generated pp-> th process using another generator and obtained a LHE file. How can I use pythia8 to do parton shower and hadronization for the th process manually?

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MadGraph5_aMC@NLO Edit question
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Last query:
2020-09-03
Last reply:
2020-09-03

Hi,

You mean from within MG5aMC and independently of event generation?
Or completely independently of MG5aMC (in which case the best is to ask to Pythia8 author obviously)

Cheers,

Olivier

Winston (adampan) said : #2

Hi Olivier,
 I mean within MG5aMC framewrok. I generated events, which is storied in a .lhe file, then how can I do parton shower and hadronazition.
Best regards.
Renqi Pan

You can then run from that process directory
./bin/madevent
then type "help pythia8" (to get the information)
in general you can type
pythia8 run_01

Cheers,

Olivier

Winston (adampan) said : #4

Hi Olivier,
 It seems that command "pythia8 run_01" is used to run pythia for events generated by Madgraph. It runs a package generated by madgraph. But I only have a .lhe file with generated events. Can I do parton shower and hadronazition through MG5aMC_PY8_interface? thanks for your kind help.
Best regards,
Renqi Pan

Hi,

In that case, it makes more sense to run Pythia8 independently of MG5aMC.

Now you can in principle try to lure MG5aMC
by creating a directory Events/run_01
and put inside your lhe file with the standard name of MG5aMC. (unweighted_events.lhe.gz)
In the past it was working but this is not a feature that is guarantee to work and all the smart automation for the default pythia8_card are off course not working in that mode.

Cheers,

Olivier

> On 3 Sep 2020, at 10:01, Winston <email address hidden> wrote:
>
> Question #692707 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/692707
>
> Status: Answered => Open
>
> Winston is still having a problem:
> Hi Olivier,
> It seems that command "pythia8 run_01" is used to run pythia for events generated by Madgraph. It runs a package generated by madgraph. But I only have a .lhe file with generated events. Can I do parton shower and hadronazition through MG5aMC_PY8_interface? thanks for your kind help.
> Best regards,
> Renqi Pan
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

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