Could not find cross-section and event number information in Pythia8 log

Asked by Andres Abreu on 2019-11-10

Hello Experts,

I'm producing the following process:

define j = b b~ p
generate p p > t t~
add process p p > t t~ j
add process p p > t t~ j j

with jet matching turned on, and every time it gets to the Pythia stage I get the following error:

Command "generate_events run_05" interrupted with error:
InvalidCmd : Could not find cross-section and event number information in Pythia8 log

I check the log in Events/run_05/PY8_parallelization/split_0/PY8_log.txt, and the cross-section is listed as 0 for some reason. I'm not sure where the problem is exactly and any help would be appreciated.

Thanks,
Andrés

Question information

Language:
English Edit question
Status:
Answered
For:
MadGraph5_aMC@NLO Edit question
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Last query:
2019-11-10
Last reply:
2019-11-11

Hi,

Can you do a proper 4 (or 5) flavor computation?
You are trying to do a mix of both which is likely to be a mess to
setup the run_card/pythia card in a meaningfull way.

I guess the best would be to do
import model sm-no_b_mass
# note that p. and j are now 5 flavor
generate p p > t t~
add process p p > t t~ j
add process p p > t t~ j j

Cheers,

Olivier

> On 10 Nov 2019, at 23:52, Andres Abreu <email address hidden> wrote:
>
> New question #685735 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/685735
>
> Hello Experts,
>
> I'm producing the following process:
>
> define j = b b~ p
> generate p p > t t~
> add process p p > t t~ j
> add process p p > t t~ j j
>
> with jet matching turned on, and every time it gets to the Pythia stage I get the following error:
>
> Command "generate_events run_05" interrupted with error:
> InvalidCmd : Could not find cross-section and event number information in Pythia8 log
>
> I check the log in Events/run_05/PY8_parallelization/split_0/PY8_log.txt, and the cross-section is listed as 0 for some reason. I'm not sure where the problem is exactly and any help would be appreciated.
>
> Thanks,
> Andrés
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

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