Upsilon Cross Section

Transcription

1 Upsilon Cross Section Michael Meier, Matthew Jones Purdue University CDF Collaboration August 7, /29

2 Upsilon Cross Section d dp T dy 2 Br( ( ns) ) A N ( ns) L dt p T y N Υ(nS) is the Υ(nS) signal yield in the fitted peak A is the geometric detector acceptance depending on valid region of detector ε is the reconstruction efficiency with selection cuts for fiducial muons L dt is the integrated luminosity 2/29

3 Acceptance Measured with Monte Carlo in bins of p T and run period Function of time because of dead wires, chambers, etc. Ratio of Number accepted to Total Number Generated A Number Accepted CMUP-CMU or CMUP-CMX Rapidity y < 0.6 Decay vertex z < 60 cm One muon fiducial in CMU and CMP with p T > 4 One muon fiducial in CMU or CMX with p T > 3 Valid region of detector depends on CMU, CMP, CMX Total Number Generated Rapidity y < 0.6 Accepted Total Gen 3/29 N N

4 CMU Valid Detector Regions Veto 1/3 of 8W and east end of 6E CMP Remove dead wires as a function of run number CMX Skip wedges 15 and 20 Hole for soleniod cryo (side 1, wedges 5 and 6) Miniskirts (wedges 15 to 20) missing before Run Keystone wedges (side 0, wedges 5 and 6) missing before Run Small hole on the west (side 0, wedge 14) between Run and Run /29

5 UPSILON_CMUP_CMU(_DPS) Upsilon Trigger L1_TWO_CMU1.5_LUMI_280» 2 muon stubs in CMU with pt > 1.5 GeV/c» 2 XFT tracks with pt > 1.52 GeV/c L2_CMUP1.5_PT3_CMU1.5_PT1.5DPS» 1 CMUP muon with pt > 3.04 GeV/c» 1 CMU muon with pt > 1.52 GeV/c L3_UPSILON_CMUP3_CMU1.5» 1 CMUP muon with pt > 3.0 GeV/c, Δx(CMU)<30, Δx(CMP)<40» 1 CMU muon with pt > 1.5 GeV/c, Δx(CMU)<30» 8.0 GeV/c 2 < mass(mu+,mu-) < 12.0 GeV/c 2 UPSILON_CMUP_CMX(_DPS) L1_TWO_CMX1.5_LUMI_280» 1 CMU muon stub with pt > 1.5 GeV/c, 1 CMX muon stub with pt > 1.5 GeV/c» 1 XFT track with pt > 1.52 GeV/c, 1 XFT track with pt > 2.04 GeV/c, signal in CSX L2_CMUP1.5_PT3_CSX1.5_PT2_CSX_DPS» 1 CMUP muon with pt > 3.04 GeV/c» 1 CMX muon with pt > 2.04 GeV/c L3_UPSILON_CMUP3_CMX2» 1 CMUP muon with pt > 3.0 GeV/c, Δx(CMU)<30, Δx(CMP)<40» 1 CMX muon with pt > 2.0 GeV/c, Δx(CMX)<50» 8.0 GeV/c 2 < mass(mu+,mu-) < 12.0 GeV/c 2 5/29

6 Selection Cuts Muon cuts CDF Muon Object, Δz 0 (mu1,mu2) < 5.0 cm, opposite charge (mu1,mu2), Δphi(mu1,mu2) > 2.25 degrees, z 0 < 60.0 cm CMUP CMU CMUP muon matched to XFT track p T > 4.05 GeV, Δx(CMU)<15, Δx(CMP)<40 CMU muon matched to XFT track p T > 3.05 GeV, Δx(CMU)<15 CMUP CMX CMUP muon matched to XFT track p T > 4.05 GeV, Δx(CMU)<15, Δx(CMP)<40 CMX muon matched to XFT track p T > 3.05 GeV, Δx(CMX)<50 6/29

7 vertex Efficiency XFT Trigger Level 2 Efficiency is measured with the Muon+SVT sample (jbmu) B_SEMI_CMUP4_TRACK2_D120 L1_CMUP6_PT4_NCLC64» 1 muon stub in CMU with pt > 6.0 GeV/c» 1 XFT track with pt > 4.09 GeV/c L2_CMUP6_PT4_D0_&_TRK2_D120_DPHI90_DPS» 1 XFT track with pt > 4.09 GeV/c and 1 CMUP muon» 1 SVT track with pt > 2 GeV/c, SVT chi2<15, Δphi<90 deg L3_B_SEMI_CMUP4_TRACK2_D120» 1 CMUP muon with pt > 4.0 GeV/c, Δx(CMU)<15, Δx(CMP)<40» Displaced track with d0<0.1 and with pt > 2.0 GeV/c Muon+SVT sample requires SVT so need the SVT efficiency 7/29

8 Trigger Efficiency JPsi candidates from all tracks in Muon+SVT sample Δz 0 (mu1,mu2) < 5.0 cm, opposite charge (mu1,mu2), Δphi(mu1,mu2) > 2.25 degrees Both tracks z 0 < 60.0 cm, XFT matched, XFT fiducial Require 1 CMUP muon with pt > 4.0 GeV/c, has CMUP L1 trigger, is fiducial in CMUP If both muon candidates pass these cuts, then consider the one with higher pt as the CMUP muon Require other track to be fiducial in CMU, pass CMU acceptance (be in a valid region of detector), and have pt > 3.0 GeV/c Check for hits in CMU (CdfMuon) and Δx(CMU)<15 JPsi mass plot for tracks passed and different plot for tracks failed Separate set of plots for each run period Fit peak and background in both mass plots N passed» N passed is JPsi yield in plot with tracks passed CMU N» N failed is JPsi yield in plot with tracks failed passed N Procedure repeated for CMUP and CMX with different cuts Trigger efficiency depends on path either CMUP-CMU or CMUP-CMX failed Trigger( CMUP CMU) CMUP CMU Trigger( CMUP CMX ) CMUP CMX 8/29

9 CMU Efficiency Required fiducial in CMU pass CMU acceptance pt > 3.0 GeV/c Passed Cuts has CMU hits (CDFMuon object) Δx(CMU)<15 Plots of passed and failed cuts for Run Period 10 (bottom right) Efficiency shown as a function of run period (top right) 9/29

10 CMUP Efficiency Required fiducial in CMU & CMP pass CMU and CMP acceptance pt > 3.0 GeV/c Passed Cuts has CMUP hits (CDFMuon object) Δx(CMU)<15 Δx(CMP)<40 Plots of passed and failed cuts for Run Period 10 (bottom right) Efficiency shown as a function of run period (top right) 10/29

11 CMX Efficiency Required fiducial in CMX pass CMX acceptance pt > 3.0 GeV/c Passed Cuts has CMX hits (CDFMuon object) Δx(CMX)<50 Plots of passed and failed cuts for Run Period 10 (bottom right) Efficiency shown as a function of run period (top right) 11/29

12 Trigger Efficiency Plots Trigger Efficiency is CMUP efficiency times CMU(CMX) efficiency CMUP-CMU (top plot) CMUP-CMX (bottom plot) 12/29

13 XFT Efficiency and Vertex Efficiency XFT Efficiency Measured using unbiased sample tracks from the kaon in B ± J/ψ K ± decays reconstructed with jpmm dataset XFT Vertex Efficiency Measured using minimum bias events up to run vertex Not yet included in cross section calculations! 13/29

14 Level 2 Efficiency (Previous Measurement) Previous measurement with 29 run periods instead of 28 first 5 run periods cover different run numbers Measured using JPSI_CMUP4_CMU_L2_DPS and JPSI_CMUP4_CMX_L2_DPS Requires 4 GeV/c CMUP muon in Level 2 and JPsi in Level 3 Require unbiased leg to be CMUP and pt > 4.0 GeV/c Satisfies Level 2 if has XFT track and muon CMU+CMX (red) stub in CMU or CMX within range of cells from CMU or CMX look-up tables Efficiency calculated from yield of JPsi passing and failing Not yet included Level in cross 2 requirements section calculations! CMU+CMU (black) 14/29

15 Upsilon Sample Upsilon candidates in jbmm data sample Δz 0 (mu1,mu2) < 5.0 cm, opposite charge (mu1,mu2), Δphi(mu1,mu2) > 2.25 degrees Both muons z 0 < 60.0 cm, XFT matched, XFT fiducial One muon with pt>4.05 GeV/c, other muon with pt>3.05 GeV/c CMUP-CMU CMUP muon with pt > 4.0 GeV/c, fiducial in CMUP, pass CMU and CMP acceptance, Δx(CMU)<15, Δx(CMP)<40, z 0 < 60.0 cm CMU muon with pt > 3.0 GeV/c, fiducial in CMU, pass CMU acceptance, Δx(CMU)<15, z 0 < 60.0 cm CMUP-CMX CMUP muon with pt > 4.0 GeV/c, fiducial in CMUP, pass CMU and CMP acceptance, Δx(CMU)<15, Δx(CMP)<40, z 0 < 60.0 cm CMX muon with pt > 3.0 GeV/c, fiducial in CMX, pass CMX acceptance, Δx(CMX)<50, z 0 < 60.0 cm 15/29

16 Plots of upsilon mass in bins of pt and run period for CMUP-CMU and CMUP-CMX Yields found in each bin of pt and run period 28 run periods 8 pt bins 0 to 2 GeV/c 2 to 4 GeV/c 4 to 6 GeV/c 6 to 8 GeV/c 8 to 12 GeV/c 12 to 17 GeV/c 17 to 23 GeV/c 23 to 40 GeV/c Upsilon Mass Plots CMUP-CMU Run Period 10 0 < pt < 2 GeV/c CMUP-CMU Run Period 10 2 < pt < 4 GeV/c 16/29

17 Calculations Cross Section as a function of run period Sum yield over acceptance for all pt bins Divide by luminosity in that run period (run period) L run period run period Cross Section as function of pt bin Sum yield over acceptance and efficiency for all run periods Divide by total luminosity in all run periods (pt bin) L total 1 y p 1 T 17/29 run period y A pt bins N N A pt bin,run period pt bin,run period pt bin,run period pt bin,run period run period

18 Upsilon Cross Section (run period) Yield/lum for each run period (for all pt bins) 18/29

19 Upsilon Cross Section (run period) Shows time dependence for cross section Average: ± 0.13 χ 2 = χ 2 = Average: ± 0.09 χ 2 = χ 2 = /29

20 Upsilon Cross Section (run period) Yield/(lum*eff*acc) for each run period (sum over all pt bins) 20/29

21 Upsilon Cross Section (run period) Reduced time dependence for CMUP-CMU Average: ± 4.2 χ 2 = χ 2 = /29

22 Upsilon Cross Section (run period) CMUP-CMX time dependence needs more analysis Average: ± 7.0 χ 2 = χ 2 = /29

23 Current Work for y < 0.6 Previous Measurements CMUP-CMU = ± 4.2 pb CMUP-CMX = ± 7.0 pb D0 Run II (1.96 TeV) for y < 0.6 PRL 94, (2005): 732 ± 19(stat) ± 73(syst) ± 48 (lumi) pb PRL 100, (2008): 628 ± 16(stat) ± 63(syst) ± 38 (lumi) pb CDF Run I (1.8 TeV) for y < 0.4 PRL 88, (2002): 680 ± 15(stat) ± 18(syst) ± 26 (lumi) pb PRL 75, 4358 (1995): 753 ± 29(stat) ± 72(syst) pb 23/29

24 Upsilon Cross Section (pt) No Level 2 Eff Yield/(lum*eff*acc*Δy*Δpt) for each pt bin (for all run periods) 24/29

25 Upsilon Cross Section (pt) No Level 2 Eff Log scale for Yield/(lum*eff*acc*Δy*Δpt) 25/29

26 Future Work Reduced time dependence for CMUP_CMU CMUP_CMX still shows slight time dependence Look into CMX muons and phi dependence Include Level 2 efficiency Not yet included in cross section calculations! Level 2 Efficiency CMU+CMU (black) CMU+CMX (red) 26/29

27 Backup Slides 27/29

28 CMP Dead Wires JPsi signal reconstructed in the Muon+SVT sample (jbmu) Monte Carlo sample of muons used to map occupancy of CMP chambers CMP occupancy depends on chamber number, due to different material in front of the various regions of the detector Assume ratio of number of counts in a given CMP chamber to total number of counts in the CMP system is the same in data and Monte Carlo Expected number of counts (N expected ) in a CMP chamber (i) in a run given by: Must have 100 counts (mu) in a CMP chamber MC, i N expected,i NData, total NMC, total Runs are combined to have the expected number of counts in a chamber Measure the actual number counts (N actual ) in the same set of runs Compute the Poisson probability to count N actual given N expected Consider the CMP chamber (wire) dead for probability < 1% 28/29 N

29 Plot of CMP Dead Wires Dead CMP wire number vs Run Index (run number) Only bins with probability < 1% are filled 29/29