The jet cluster for e+ e- collider

[chenning]

Hi, I am trying to ask about the issue of the jet clustering for the e+ e- collider simulation. I am studying the Higgs productions and decays on the e+e- machine, such as at ILC. I started with running the events to the parton level and then pythia level at the madgraph5. Afterwards, I am supposed to do jet cluster. My problem is for the e+e- collider, I do not have a specific detector configuration. In my previous experience of the LHC simulations, I can directly pass the pythia.hep output files into the delphes to run the detector simulation by using the ATLAS/CMS card files provided therein. However for the e+e- collider, it doesn't seem reasonable to do this. So I am wondering if I can still use delphes to only make the jet cluster without performing the detector simulations.

[Michele Selvaggi]

Hi,

first note that we will release a Delphes version suitable for TLEP (and therefore ILC) this (or next) week.
You can already find find a prerelease with a TLEP card here
​http://cp3.irmp.ucl.ac.be/downloads/Delphes-3.0.13.pre1.tar.gz

If you really want to run jet clustering only, you can use any existing card. You should then simply look at the GenJet collection (jets clustered from stable particles) and Particle collection (hard-scattering, unstable and stable particles) and ignore the other branches that concern reconstructed quantities.

Michele

[chenning]

Hi,

I made a quick test run by using the TLEP card such as:

./DelphesSTDHEP examples/delphes_card_TLEP.tcl delphes_output.root pythia.hep

It turns out the delphes cannot access 'Calorimeter/eflowNeutralHadrons' and 'Calorimeter/eflowPhotons' in the TreeWriter. It cannot access inputarrays of 'Calorimeter/eflowPhotons' and 'Calorimeter/eflowNeutralHadrons' in the EFlowMerger module. I commented these lines afterwards, then I could perform the delphes run as above. Would you please check out if there is anything wrong here or it is due to my input sample? thanks a lot for this.

[Michele Selvaggi]

Hi,

did you try to run the new card inside with Delphes-3.0.13.pre1 or with a previous version? The TLEP card is not supposed to work with an older Delphes version since the output collection produced by the calorimeter module are now

Calorimeter/eflowNeutralHadrons
Calorimeter/eflowPhotons

instead of

Calorimeter/eflowTowers

I just tried to download the tar file I indicated before, compile and run with the command line you quoted I have no error messages.