Upsilon Cross Section: Applied to one p T bin in CDF data

1. Upsilon Cross Section:Applied to one pT bin in CDF data Matthew Jones Purdue University B Production and Decay Meeting

2. Recent Developments • Bug fix (actually fixed mid April) • improved agreement between CMU and CMX that plagued the results presented in early April • Self consistent efficiency definition • Constrained using J/ψdecays from μ+SVT dataset • Run dependence in CMP efficiency • Possible evidence for run dependence in ϒ(1S) cross section? • Various cross checks B Production and Decay Meeting

3. Acceptance Definition • is the acceptance: • Probability that final state is within the fiducial acceptance of the detector • Analysis is performed using CdfMuon objects in data and Monte Carlo • The Monte Carlo actually measures where ≈ B Production and Decay Meeting

4. Muon Scale Factors • We introduce the muon scale factors so that = • COT hit embedding analysis (CDF Note 6394) gives: • Measure using unbiased leg of J/ψ reconstructed in μ+SVT dataset. • But this leg still has a bias from XFT. • Measure XFT efficiency from unbiased K+ in from the di-muon dataset. B Production and Decay Meeting

5. XFT Efficiency Matched with XFT track Not matched with XFT track • Only requirement on kaon is that it is found in defTracks and satisfies fiducial cuts: z(R=136 cm) < 155 cm, |z(COT SL)| > 1.5 cm and pT> 3 GeV/c. B Production and Decay Meeting

6. Muon Efficiency • Require unbiased leg to satisfy fiducial cuts, and to be well within the fiducial acceptance of the muon chambers: • MuonFiducialTool + additional cuts on B Production and Decay Meeting

7. Muon Efficiency • Muon efficiency for XFT tracks • Scale factors: B Production and Decay Meeting

8. Muonquality cuts • In addition, require to be compatible with L1 trigger efficiency parameterization… • Which one? • mu.cmu().chsqX()? • mu.cmu().chsqXPosition()? • Methods in MuonUser/StubChisquare.hh? • chsqXPosition() < 9 is essentially fully efficient in both CMU and CMX. • StubChi2Cmu(pt,dx,dphi) < 9: B Production and Decay Meeting

9. Other efficiencies • Vertex cuts: |z0|<60 cm, |Δz0|<5 cm. • Require generated decays satisfy this cut. • Efficiency measured in CDF notes 7935, 8289: • Radiative losses: • Generate decays with PHOTOS • Fit with single Gaussian as is done in the data • Fitted yield is 90% of the number of decays generated • Should probably also fit using a crystal ball function. B Production and Decay Meeting

10. CMP Efficiency • Parameterized as a function of 1/pT in 48 “wedges” (24 east + 24 west). • Added an run-dependent scale factor to account for changes in efficiency in some regions. B Production and Decay Meeting

11. Luminosity Calculation • Most of the data was recorded with DPS triggers. • Effective luminosity retrieved from database using DFCLuminosityTool. • Luminosity put into database was apparently calculated using • Undefined when Pj = 0 in run section j. B Production and Decay Meeting

12. Extreme example: run 209318 • This was a long 19 hour run with initial luminosity of 40x1030 cm-2s-1… Integrated luminosity = 2.03 pb-1. • Initial prescale = 10  1 after first ½ hour of running. • Integrated luminosity in each 30 second run section varies from 1.5 nb-1 to 0.6 nb-1. • L2 upsilon trigger cross section is about 1.5 nb. • 10% chance of no triggers in a run section at start of run • 40% chance for no triggers in a run section by end of run. • But DFCLuminosityTool returns 0.17 pb-1. B Production and Decay Meeting

13. Alternative to DFCLuminosityTool • Correlate L2 prescale changes with run sections using • Event number (earlier data) • Time since start of run (later data) • Assumes prescale changes are accurately recorded in the online database • Be careful about runs where there were no prescale changes • Early trigger tables which did not use DPS • LUMI_280 triggers which were always disabled B Production and Decay Meeting

14. Luminosity Comparison • Most runs agree at the level of 0.25% • No attempt to interpolate within run sections • No difference for unprescaled triggers • Biggest difference for long, low luminosity runs. B Production and Decay Meeting

15. Results in 8.5-10.5 GeV/c bin Good agreement with results from Run I… maybe just be lucky. B Production and Decay Meeting

16. Polarization Parameters Background 3S 2S 1S Collins-Soper frame S-channel helicity frame B Production and Decay Meeting

17. Projections: Collins-Soper frame B Production and Decay Meeting

18. Projections: S-channel helicity frame B Production and Decay Meeting

19. Time Dependence? • Better than it was before. • Still not completely consistent with a constant cross section. • Some variation in CMX in early runs could be due to acceptance. • Unlikely to be purely statistical. • How to translate this into a systematic uncertainty? = 23.6/9 35.4 6.0 18.1 17.8 7.8 B Production and Decay Meeting

20. Summary • Self-consistent definition and measurement of efficiencies and muon scale factors was a useful cross check. • Search for time-dependent effects yielded significantly improved understanding of some effects but no obvious culprit. • Possibly still some time dependence in measured cross sections. • Fit behaves quite well now. • Consider analyzing other pT bins next? B Production and Decay Meeting