DelphesPythia8

[Daschm]

Hi Delphes Developers,

I recently found the DelphesPythia8.cpp file among the readers and tried to make it work. I compiled the source code and ran it and everything works... except for the fact that my .root files always end up mostly empty. The number of events are correct and also the eventwise information is stored (as well as GenParticle information). However, jets, electrons, muons are all empty.

If I however run Pythia standalone with the same .in file and process the outgoing .hepmc file with DelphesHepMC with the same detector card, I do get filled .root files. Therefore it should have nothing to do with the pythia setup or the detector card used.

Before I investigate this issue further I wanted to generally ask whether this DelphesPythia8.cpp code has actually been tested and should work (because then the problem is clearly somewhere on my side) or if the file itself could contain bugs.

Sincerly
Daniel Schmeier

[Pavel Demin]

I can't say that DelphesPythia8.cpp is bug free. But looking through the Delphes tickets, I'd say that there is at least one person using DelphesPythia8.cpp:

https://cp3.irmp.ucl.ac.be/projects/delphes/ticket/335

https://cp3.irmp.ucl.ac.be/projects/delphes/ticket/362

I've recently adapted DelphesPythia8.cpp to the latest Pythia version and it's possible that I introduced new bugs.

Here are the changes:

https://cp3.irmp.ucl.ac.be/projects/delphes/changeset?reponame=git&new=3e276d4a107ef1a21c44b912b1cffd30afdef462@readers/DelphesPythia8.cpp&old=1fa50c28409a44b952b4b2f1a0c4f30a60f8cc50@readers/DelphesPythia8.cpp

May be there is something wrong with the particle status code in this new version.

I'd be interested to reproduce this problem. Could you send me your configuration file for Pythia?

[Daschm]

Hi,

I now downloaded your newest Delphes Version, compiled the DelphesPythia8.cpp by linking to Pythia8.2 and it works like a charm! Even though I am pretty sure I did more or less the same thing before I opened this ticket.

Maybe I linked to Pythia 8.1 before and introduced issues there... well, in any event: Sorry for the invonvenience. Should I encounter the problem again I will come back to you.

Cheers
Daniel