Errors running DelphesPythia8_EDM4HEP

FCCAnalysis
1

Hello,

When I follow and run the procedure in the FCCanalysis tutorial to generate and simulate events with DelphesEDM4Hep everything works properly and I can produce the root file.
For my study, I am going to produce a root file with SUSY processes in EDM4hep as an input file for FCCAnalysis. The SUSY processes that I want to use are “SUSY:gg2squarkantisquark” and " SUSY:qqbar2squarkantisquark" in the Pythia card. However, when I compile the “DelphesPythia8_EDM4HEP” command I faced the following errors:

PYTHIA Error in StringFragmentation::fragment: stuck in joining
PYTHIA Error in Pythia::next: hadronLevel failed; try again
PYTHIA Abort from Pythia::next: parton+hadronLevel failed; giving up

*** Break *** segmentation violation

The Pythia card that I use is:

Random:setSeed = on
Main:numberOfEvents = 1000 ! number of events to generate
Main:timesAllowErrors = 5 ! how many aborts before run stops

! 2) Settings related to output in init(), next() and stat().
Init:showChangedSettings = on ! list changed settings
Init:showChangedParticleData = off ! list changed particle data
Next:numberCount = 100 ! print message every n events
Next:numberShowInfo = 1 ! print event information n times
Next:numberShowProcess = 1 ! print process record n times
Next:numberShowEvent = 0 ! print event record n times

! 3) Beam parameter settings. Values below agree with default ones.
Beams:idA = 2212 ! first beam, p = 2212, pbar = -2212
Beams:idB = 2212 ! second beam, p = 2212, pbar = -2212
Beams:eCM = 100000 ! CM energy of collision

! 4) Read SLHA spectrum (a few examples are provided by default)
SLHA:file = SPheno.spc
#SLHA:useDecayTable = on

! 5) Process selection
SUSY:qqbar2squarkantisquark = on
SUSY:gg2squarkantisquark=on

! 6) Settings for the event generation process in the Pythia8 library.#
PartonLevel:MPI = on ! no multiparton interactions
PartonLevel:ISR = on ! no initial-state radiation
PartonLevel:FSR = on ! no final-state radiation
HadronLevel:Hadronize = on ! no hadronization

The Delphes card is “FCChh.tcl” and the command line to run is " DelphesPythia8_EDM4HEP FCChh.tcl edm4hep_IDEA.tcl Pythia-Stop_pair-production.cmd Stop_Process.root "

Could you please guide me on how I can resolve this problem? Many thanks in advance.

Best regards,
Safura

2

Dear Safura,
This seems a problem with the Pythia8 cards for which we would need a Pythia8 expert; perhaps you can get some help at Issues · Pythia / releases · GitLab .

In the meantime, you can try the cards in standalone with the Pythia8 example main03.cc: this might help in isolating the problem. To do that, after enabling key4hep, check $PYTHIA8/share/Pythia8/examples.

If you are not able to build main03, you can try to run /afs/cern.ch/user/g/ganis/public/fcc/pythia8/bin/main03.
Note that the cards file must be called main03.cmnd.

Hope it helps.
G Ganis

3

Dear Ganis,

Sorry for the late response!
The mentioned directory and Pythia example files were so useful and I’ve resolved my problem. Thank you so much for your advice.

Best regards,
Safura