Invalid event format in Delphes when varying qcut

Asked by Joel Jones on 2018-03-13

I am running the MadGraph + Pythia8 + Delphes chain, and I am getting a problem similar to this one:

I have installed the latest versions of MadGraph, hepmc, Delphes and ExRootAnalysis. I am running on a Fedora system, with a global root installation (this also happens for a locally installed root v6.12.06).

The strange thing is that this problem happens for specific values of qcut. The process I am looking at is p p > nu nu~ + Jets (up to four), with xqcut = 10 GeV. If I set qcut = 15 GeV, there is no problem, and Delphes runs normally. If I change qcut = 20 GeV or 30 GeV, then I get an "** ERROR: invalid event format" on the Delphes log.

No idea how to proceed. Could I get any help?

Question information

English Edit question
Needs information
MadGraph5_aMC@NLO Edit question
Olivier Mattelaer Edit question
Last query:
Last reply:
Joel Jones (n-jones-j) said : #1

Hi, the issue was eventually solved here:

It was related to the systematics. Once I run off systematics, I call generate_events and everything works smoothly.

A different problem appears later, though. If I call madevent, and then just run pythia8 run_XX, I get a new error:

Merging results from the split PY8 runs...
INFO: Create matching plots for Pythia8
Command "pythia8 run_06" interrupted with error:
KeyError : 'mgruncard'
Please report this bug on
More information is found in '/home/jjones/Programs/MG5_aMC_v2_6_0/ppNuNu2/run_06_tag_3_debug.log'.
Please attach this file to your report.

The Pythia hepmc event file is created without a problem, though, and I can use it with Delphes later.

Can you include the relevant part of the error log file?


Can you help with this problem?

Provide an answer of your own, or ask Joel Jones for more information if necessary.

To post a message you must log in.