Preliminary Evaluation of PID Performance Steve Kahn 21 July 2004 11/7/2015 What Have We Simulated? The data sample generated is 20K events. Muons are started at.
Download ReportTranscript Preliminary Evaluation of PID Performance Steve Kahn 21 July 2004 11/7/2015 What Have We Simulated? The data sample generated is 20K events. Muons are started at.
Preliminary Evaluation of PID Performance Steve Kahn 21 July 2004 11/7/2015 1 What Have We Simulated? The data sample generated is 20K events. Muons are started at the beginning of the downstream SciFi. x=5 cm; x’=2 mr. The decay electron sample is enhanced by decreasing the decay length by a factor of 5. Steve Kahn 17 July 2004 We want to keep the proper decay electron energy distribution. We want to correct for having no upstream detector. We need enough events in our sample. Mice Detector Meeting Page 2 Events are Organized to Contain All Tracks Produced from the Initial Muon I have put together a simple skeleton program for looking at correlated information between detector units. This program operates on Digitization data. Reconstruction data is not readily available for Pid detectors at this point. We do not have a useful data summary format. Data shown is not definitive at this point. The mean number of track-like objects is 1.9. Most of the additional tracks are some sort of electron. Steve Kahn 17 July 2004 Mice Detector Meeting Page 3 X vs. Y at Different Detectors for Muons Steve Kahn 17 July 2004 Mice Detector Meeting Page 4 X vs. Y at Different Detectors for Electrons Steve Kahn 17 July 2004 Mice Detector Meeting Page 5 Comparison of the Radial Distributions of Muons and Electrons at the Different Detectors Steve Kahn 17 July 2004 Mice Detector Meeting Page 6 Counting Tracks in the PID Detectors Sub Detector Muons Electrons SciFi Tof II Ckov II EmCal 19770 19632 19024 14832 2531 933 853 171 Electrons E>2.5 MeV 422 341 283 70 The above table shows the true identity of track traversing the various down stream detectors. The electron energy cut (2.5 MeV) corresponds to the electron threshold in the Ckov II with a n=1.02 radiator. Steve Kahn 17 July 2004 Mice Detector Meeting Page 7 What Do We Mean by Electron? Geant will produce electron tracks in a number of ways: The decay of muons. These are a background that we are concerned about. These electrons have energies ~1/3 of the muon. These we want to remove. Knock on electrons from the muon traversing material. They are generated in TofII or CkovII. They typically have energies of the order of 0.5 MeV. Most should be below Ckov threshold with n=1.02 (2.5 MeV). It is relatively rare that the knock-on electrons will surpass this threshold. They will have larger dE/dx in the Tof which might cause good muons to be rejected. Knock on electrons that are easily matched to the muon are removed. Steve Kahn 17 July 2004 Mice Detector Meeting Page 8 Time Difference of a Track Traversing the SciFi to the TOF2 Steve Kahn 17 July 2004 Mice Detector Meeting Page 9 Time of Flight from Tof2 to Ckov2 Steve Kahn 17 July 2004 Mice Detector Meeting Page 10 Time of Flight from Tof2 to EmCal Steve Kahn 17 July 2004 Mice Detector Meeting Page 11 EmCal Separation of electrons from muons Electrons Muons Steve Kahn 17 July 2004 Mice Detector Meeting Page 12 Separation of from e using Barycentric variable in EM Calorimeter Steve Kahn 17 July 2004 Mice Detector Meeting Page 13 Steve Kahn 17 July 2004 Mice Detector Meeting Page 14 EmCal e/ Selection Criteria My baricenter coordinate distribution looks similar to Alessandria’s, however my E1 vs E1_fraction plot shows a wider muon region. This needs to be understood. My selection choice from the EmCal is the following: If Zbari<30 mm it is an electron. If E1/E1fract < 50 it is an electron. Else it is a muon. Selected as: Muon Electron Steve Kahn 17 July 2004 Is this OK? True Muon 13907 919 True Electron 8 59 Mice Detector Meeting Since we are interested in Muon purity, this maybe. Page 15 Ckov II Selection Criteria The Ckov II Detector Response currently does not have sufficient information to properly produce a decision based on the measurements. The following procedure was used: Require a Tof II signature or the selection is indeterminate. If the track crossing the Ckov radiator has >0.98 (the electron threshold) and the Ckov II – Tof II time difference is between 0.21.0 ns, then it is an electron. Else if the energy is greater than 75 MeV it is a muon. Else it is indeterminate. Selected as: True Muon True Electron 19023 558 Muon 0 41 Electron Steve Kahn 17 July 2004 Mice Detector Meeting Page 16 Global Particle Identification In this analysis we have defined the Global ID to be isElectron = ckov.isElectron .OR. emCal.isElectron notDetermined = ckov.notDetermined .AND. emCal.notDetermined isMuon = .NOT. isElectron We have ignored some of the Tof information. Since we only modeled downstream detector Tof I timing is not available. From the earlier transparency, we expect that the TofII-TofI time difference should be a powerful discriminate for distinguishing decay electrons from muons. Selected as: True Muon True Electron 19609 8 Muon 23 59 Electron Steve Kahn 17 July 2004 Mice Detector Meeting Page 17 Conclusions These results are quite preliminary. There are enough inconsistencies present, that one should expect these numbers to change. The EmCal selections plots are somewhat different from those previously shown. These differences need to be understood. The Ckov selections are not based on PMT photo-electrons captured. They are based on simple kinematics. This needs to be done better. The Tof time differences are not effectively used in the analysis. There is much that can be done to improve this in the future. Steve Kahn 17 July 2004 But we have gotten started. Mice Detector Meeting Page 18