Launching pythia-pgs with the LHE file

Asked by Maksym Ovchynnikov on 2018-03-29

I'm sorry for the following stupid questions, but...

I generated the process p p > b b~ in MG5. Then I want, using corresponding generated LHE file, simulate events with produced B-mesons.

1) Is this possible without installation of standalone Pythia, but with using of "built-in" package pythia-pgs?

2) If yes, which terminal commands should I use for this?

3) If yes, then in order to change the properties of the run, should I edit something like "pythia card"?

3) If yes, what will be the format of outputted data: some text file, graphic or terminal output?

Question information

Language:
English Edit question
Status:
Answered
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Last query:
2018-03-29
Last reply:
2018-03-29

Hi,

> 1) Is this possible without installation of standalone Pythia, but with using of "built-in" package pythia-pgs?

You should know that pythia-pgs is deprecated.
PY6 author does not fix bug in that code anymore since ~5 years and have stop any kind of support since ~3 years.
PGS is actually not supported since ~8 years
the interface to MG5 is also not supported anymore (we know some bugs associated to that interface but do not plan to fix those)

So you can use pythia-pgs package but you are completely without any safety net.
If you have an issue no one will help you.

> 2) If yes, which terminal commands should I use for this?

if you are using 2.6.1, asking for
shower=PY6
will run pythia6

> 3) If yes, then in order to change the properties of the run, should I edit something like "pythia card"?

yes (but do not ask me what to put inside that file)

> 3) If yes, what will be the format of outputted data: some text file, graphic or terminal output?

py6 returns stdhep output file. This is a binary output format (I have no idea on how to read the content of such file).

 Cheers,

Olivier

> On 29 Mar 2018, at 21:27, Maksym Ovchynnikov <email address hidden> wrote:
>
> New question #667349 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/667349
>
> I'm sorry for the following stupid questions, but...
>
> I generated the process p p > b b~ in MG5. Then I want, using corresponding generated LHE file, simulate events with produced B-mesons.
>
> 1) Is this possible without installation of standalone Pythia, but with using of "built-in" package pythia-pgs?
>
> 2) If yes, which terminal commands should I use for this?
>
> 3) If yes, then in order to change the properties of the run, should I edit something like "pythia card"?
>
> 3) If yes, what will be the format of outputted data: some text file, graphic or terminal output?
>
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Maksym Ovchynnikov (name-xxx) said : #2

Dear Olivier,

thank you for your help! However, due to my poor knowledge I'm still in problem.

1) So, in order to live without bugs, instead of pythia-pgs I should use simply pythia8 package?

2) I just have found a question https://answers.launchpad.net/mg5amcnlo/+question/221589 . Am I right that its author asks about the same thing that I ask?

If yes, I've stucked with the problem: I don't know which "./bin/madevent" should I do. One of "them" is located in $PROCESSOUTPUT/madevent, another one in $/PROCESSOUTPUT. Could you please help with this stupid question?

3) And what about py8? Similar binary output?

> 1) So, in order to live without bugs, instead of pythia-pgs I should use
> simply pythia8 package?

No code are bug free. Especially in science.
The difference is if you face one bug (or if you have doubt/question)
for py6 no expert will help you (except advise you to switch to pythia8)
while for pythia8 you will get advise, patch,...

So if you are not yet an Pythia6 expert, I do not see any good reason why
you should start to learn Pythia6 today.

> 2) I just have found a question
> https://answers.launchpad.net/mg5amcnlo/+question/221589 . Am I right
> that its author asks about the same thing that I ask?

This sounds a very old question, at that time we were not proposing an interface to py8.
The question is more how to run Delphes than anything else. and the second part of the question
is how use the MG interface to shower events that are not generated by him.

> If yes, I've stucked with the problem: I don't know which
> "./bin/madevent" should I do. One of "them" is located in
> $PROCESSOUTPUT/madevent, another one in $/PROCESSOUTPUT. Could you
> please help with this stupid question?

Are you running with gridpack and unpack those?
In principle you should not have a directory
> $PROCESSOUTPUT/madevent

The way, I can see such directory created is for the following workflow
1) you run ./bin/generate_events and ask for a gridpack run
2) you unpack the gridpack where it is created
3) the unpacking of the gridpack create one file (run.sh) and a directory madevent

> 3) And what about py8? Similar binary output?

No they output hempc file which is a text file well documented (I have wrote a python parser in a couple of hours for example)
and you have an official C++ library to provide efficient way to read such file.

Cheers,

Olivier

> On 29 Mar 2018, at 22:13, Maksym Ovchynnikov <email address hidden> wrote:
>
> Question #667349 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/667349
>
> Status: Answered => Open
>
> Maksym Ovchynnikov is still having a problem:
> Dear Olivier,
>
> thank you for your help! However, due to my poor knowledge I'm still in
> problem.
>
> 1) So, in order to live without bugs, instead of pythia-pgs I should use
> simply pythia8 package?
>
> 2) I just have found a question
> https://answers.launchpad.net/mg5amcnlo/+question/221589 . Am I right
> that its author asks about the same thing that I ask?
>
> If yes, I've stucked with the problem: I don't know which
> "./bin/madevent" should I do. One of "them" is located in
> $PROCESSOUTPUT/madevent, another one in $/PROCESSOUTPUT. Could you
> please help with this stupid question?
>
> 3) And what about py8? Similar binary output?
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Can you help with this problem?

Provide an answer of your own, or ask Maksym Ovchynnikov for more information if necessary.

To post a message you must log in.