DelphesCMSSWLite backwards compatibility

[Hussein Abdallah]

Hello,

I'm trying to run samples (retrieved from DAS) through DelphesCMSFWLite and I believe there is an incompatibility issue between the samples and my Delphes version (3.0.9). One of the samples, for instance, is /store/generator/Summer13/GluGluToHHToGGBB_M-125_14TeV-powheg-pythia6/GEN/UpgrdPhase1Age0DES_DES17_61_V5-v1/00000/669EC837-0DF0-E211-AB12-BCAEC5329716.root and comes from a dataset generated using the following release of CMSSW: CMSSW_6_1_2_SLHC2_patch3.

Now when I try to run this sample through Delphes-3.0.9 on a tier 3 machine using this release CMSSW_6_0_1_PostLS1v2_patch4 of CMSSW (which is the latest one available on my machine), the following error occurs:

** Reading root://xrootd.unl.edu//store/generator/Summer13/GluGluToHHToGGBB_M-125_14TeV-powheg-pythia6/GEN/UpgrdPhase1Age0DES_DES17_61_V5-v1/00000/669EC837-0DF0-E211-AB12-BCAEC5329716.root
terminate called after throwing an instance of 'edm::Exception'
  what():  An exception of category 'ProductNotFound' occurred.
Exception Message:
No branch was found for 
  type ='edm::Wrapper<std::vector<reco::GenParticle> >'
  module='genParticles'
  productInstance=''
  process=''

Aborted

I'm thinking I might have to upgrade to Delphes-3.0.10. Is there a release of Delphes-3.0.10 available yet somewhere?

Thanks in advance,
Hussein

[Pavel Demin]

Dear Hussein,

Normally, both Delphes 3.0.9 and 3.0.10 should be able to read CMSSW files.

It's the CMSSW version that is important.

I've just tried to open the same file

root://xrootd.unl.edu//store/generator/Summer13/GluGluToHHToGGBB_M-125_14TeV-powheg-pythia6/GEN/UpgrdPhase1Age0DES_DES17_61_V5-v1/00000/669EC837-0DF0-E211-AB12-BCAEC5329716.root

using CMSSW_6_1_2_SLHC2_patch3 and Delphes-3.0.9.

I get the same error message as you do.

When I look at the file contents using ROOT's TBrowser I don't see any recoGenParticles branch.

The only branch that I see is LHEEventProduct and it contains only 8 entries per event.

So, I'd say that this file contains only matrix element level events before showering/hadronization.

According to CMS DAS the dataset name is

/GluGluToHHToGGBB_M-125_14TeV-powheg-pythia6/Summer13-UpgrdPhase1Age0DES_DES17_61_V5-v1/GEN

Unfortunately, I can't find in CMS DAS any information neither about children/parents of this dataset nor about the configuration files used to generate this dataset.

However, there is a GEN-SIM dataset with the same name

/GluGluToHHToGGBB_M-125_14TeV-powheg-pythia6/Summer13-UpgrdPhase1Age0DES_DES17_61_V5-v1/GEN-SIM

I've tried to run Delphes 3.0.9 over one of the files

root://xrootd.ba.infn.it//store//mc/Summer13/GluGluToHHToGGBB_M-125_14TeV-powheg-pythia6/GEN-SIM/UpgrdPhase1Age0DES_DES17_61_V5-v1/00000/04182DDA-BFF1-E211-B019-6C3BE5B59058.root

and everything worked well.

Could you try to use the GEN-SIM dataset instead of the GEN dataset?

Regards,

Pavel