Checking different tracking algorithms with a di m sample

1. Checking different tracking algorithms with a dim sample Ryan J. Hooper (University of Notre Dame: 25, UofM: 23) • Start with sample of p11.11 data on SAM • recoA_reco_dimuon_third_merged%tk-p11.11-%.root • Look at the six different algorithms: (gtr,htf,gtrela,htfela,gtrhtf,aa) • Sample has ~30K events / algorithm (gtrela has 21K, htfela has 28K) • Ran each algorithm sample through the exact same analysis macros • Do fits and compare to known values • Observations

2. J/Psi m mM = 3096.9 MeVGmm = 5 keV • “Tight” Muons matched (h,f) to Gtr401@DCA tracks (“Gavin’s” Matching) • Matching requires both tracks to have pT > 2.5 GeV • Track nhits > 11 • Fit peak with Gaussian + Linear BK

3. J/Psi m m

4. J/Psi m m

5. Upsilon m mM1S = 9460 MeV G(1S)mm = 1.3 keV • “Tight” Muons matched (h,f) to Gtr401@DCA tracks (“Gavin’s” Matching) • Require both tracks to have pT > 2.5 GeV • Track nhits > 11 (SAME CUTS AS J/PSI !) • Fit peak with Gaussian + Linear BK

6. Upsilon m m

7. Upsilon m m

8. Z m mM = 91.19 GeVGmm = 84 MeV • “Tight” Muons matched (h,f) to Gtr401@DCA tracks (“Gavin’s” Matching) • Match requiring both tracks to have pT > 2.5 GeV • Track nhits > 11…...Then require both tracks to have pT > 15 GeV!!! • Fit peak to a Gaussian + Linear BK

9. Z m m

10. Z m m

11. Observations • Three different resonances were look at J/Psi, Upsilon and Z • Saw a few events that might have some duplication of tracks or some other strange behavior ??? • Run: 152415 152420 • Event: 532207 1033338

12. Observations (cont.) • At lower masses the aa and gtrela algos seemed to over measure the mass while gtrhtf, htf and gtr appears to under measure! • Overall the htfela algorithm looked to perform the best over all the mass scales !