Including PDF reweights in ROOT tree

[Jake]

Hi,

I'm trying to study the effect of PDF uncertainties on samples generated with MadGraph and Sherpa. With MadGraph, for example, I generate 145 weights per event from scale and PDF variations. These weights are present under the Rwgt.Weights branch of my LHE file, and I can see all the weights in my HEPMC file, but in the Delphes ROOT file all I have are the weights in the Events.Weights branch, which comprises one weight per event. Is there something I can add to the Delphes card to carry over all weights from the HEPMC file to the Delphes ROOT tree?

Thanks a lot.

[Pavel Demin]

Currently, the branch with multiple weights is present in the .root files produced by DelphesCMSFWLite, DelphesLHEF and DelphesPythia8.

It's possible to add the branch with multiple weights to DelphesHepMC. DelphesHepMC.cpp and DelphesHepMCReader.* should be modified similarly to DelphesLHEF.cpp and DelphesLHEFReader.*.

[Pavel Demin]

The modified DelphesHepMC.cpp and DelphesHepMCReader.* files are now in the git repository:
d203a374af4741c1b47dbb69f1adc88adc998ec2/git

[Jake]

Hi Pavel,

Thanks so much! This solved my problem.