MadAnalysis 5

fastjet - reconstructed Jet information

Asked by Ioannis Tsinikos

Dear MadAnalysis team,

I am using the fastjet package for jet clustering in the process p p -> t tbar W -> decay. I am interested in asymmetries concerning the 2 b-tagged final jets. After fastjet I can get output.lhe or output.lhco file format. Is there a way to distinguish between the jets coming from b and bbar? By looking at the output.lhe format file, I notice that the mother-daughter link information is lost for the reconstructed objects. Do I have to specify something in order to maintain this information?

It is mentioned in arXiv:1309.7831v1 that this output does not follow exactly the lhe, lhco conventions. Does this mean that there is crucial information lost in this output? Should it be avoided for analysis?

Thank you in advance,
Ioannis

Question information

Language:
English Edit question
Status:
Solved
For:
MadAnalysis 5 Edit question
Assignee:
Benjamin Fuks Edit question
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Ioannis Tsinikos (ioannis-tsinikos) said : 		#1

Dear MadAnalysis team,

after contact via e-mail with Benjamin Fuks, concerning the 2nd part of my question the lhe, lhco output of the fastjet package in MadAnalysis contains all the necessary information for analysis.

Concerning the 1st part, the mother-daughter link is lost for all the intermediate and reconstructed objects, if one uses HERWIG for hadronization (this is the one I was using).

By creating some new events hadronized with PYTHIA 6, the mother-daughter link is kept for all the intermediate and all the reconstructed objects except the jets, b-tagged or not (status code = +1, pdg code = 5, 21). I still do not know if I have to specify something in order to maintain this information specifically for the reconstructed jets.

Best,
Ioannis

Revision history for this message
Benjamin Fuks (fuks) said : 		#2

Solved by e-mail