 |
 |
Hi, I've been running hep.lcd.recon.tracking.TrackReco on ttbar events simulated for the large detector, and I feel uncomfortable about the results I've been getting. I wonder if somebody could shed some light as to what I'm doing wrong, or whether what I'm seeing isn't unexpected. I'm focusing my study on ttbar events in the "lepton + jets" decay channel -- i.e. one of the top quarks decays to ele or muo + neutrino + b-quark, the other to three quarks. When I run TrackReco, I am able to match the primary muon track to the monte carlo track in only 58% of the events; with electrons, this figure goes down to 31% (check out plots in umaxp1.physics.lsa.umich.edu/~guillian/nlc/23-apr-1999/summary.html). What's more, the average number of charged monte carlo tracks is 45.0, while the number of found tracks is 11.6. These figures seem rather dismal. Is this expected? Or do the default track-finding paramters need to be tuned for ttbar events? Gene