1.  (2S) cross section and search for narrow resonances below the Upsilon mesons at CDF Alberto Annovi - INFN Frascati for the CDF collaboration International Workshop on Heavy Quarkonia 2008 Nara Women's University 2-5 December 2008

2. Dec 4th, 2008Alberto Annovi2 The CDF detector @ Fermilab Silicon Microstrip Tracker Drift Chamber Central Muon |  |<0.6 Solenoid Muon Extension |  |<1.1 Calorimeter system   Ｔｅｖａｔｒｏｎ p pbar ＠ 1.96 ＴｅＶ 

3. Dec 4th, 2008Alberto Annovi3  (2S) cross section

4. Dec 4th, 2008Alberto Annovi4 Why  (2S) cross section?  Charmonium production as test of QCD models  NRQCD can account for J/  and  (2S) cross- section  NRQCD *not* able to describe polarization   (2S) is clean: small feed-down from higher charmonium states  Extend differential xsec up to 30 GeV Phys. Rev. Lett. 99, 132001 (2007)

5. Dec 4th, 2008Alberto Annovi5 Measurement principle  Select a clean di-muon sample  Unbinned fit to separate  signal from backgrond  prompt  (2S) from long lived ones  fit in p T bins  Calculate acceptance, efficiency and luminosity  Get differential cross-section: 

6. Dec 4th, 2008Alberto Annovi6 Data selection  1.1 fb -1 from low-p T dimuon trigger  Trigger selection  2 central muons p T > 1.5 GeV  Off-line selection  2 central muons p T > 2 GeV  3 r-  silicon (SVX II) hits / muon  tracks, muons and vertex quality cuts  Analysis kinematical limits  2 GeV < p T (  (2S)) < 30 GeV  | y(  (2S)) | < 0.6

7. Dec 4th, 2008Alberto Annovi7 Fitting the data  Unbinned maximum likelihood fit variables  reconstructed mass  reconstructed ct  Signal likelihood  mass: Gaussian + crystal ball function  ct (prompt): double Gaussian  ct (long lived): exponential conv. Gaussian  Background likelihood  mass: 1st order polynomial  ct : combination of prompt, long lived symmetric and long lived asymmetric effective ct: only  ’ is reconstructed

8. Dec 4th, 2008Alberto Annovi8 Fit projections 5.5 < p T < 6.0 GeV 5236  (2S) signal events 4213 prompt 1023 long liv. signal events CDF preliminary 1.1fb -1

9. Dec 4th, 2008Alberto Annovi9 Acceptance and efficiency  Geometric acceptance from CDF simulation   (2S) generated uniform in , p T and y   (2S) decayed with EVTGEN  different polarization are generated  Trigger efficiency measured on data  Offline reconstruction efficiency  measured on data in combination with MC  Nominal luminosity 1.1fb -1  effective luminosity is 0.95fb -1  due to trigger dynamic prescale @ high luminosity

10. Dec 4th, 2008Alberto Annovi10 Polarization  Acceptance depends upon polarization  Acceptance and its systematics are determined assuming:  prompt :  = 0.01 ± 0.13  A=2% @ p T =3 GeV  A=20% @ p T =23 GeV  from B decays   eff = 0.35 ± 0.25 ± 0.03  A=1.5% @ p T =3 GeV  A=19% @ p T =23 GeV  Inclusive measurement uses weighted average acceptance Phys. Rev. Lett. 99, 132001 (2007)

11. Dec 4th, 2008Alberto Annovi11 Systematics uncertanities

12. Dec 4th, 2008Alberto Annovi12 Differential cross-section CDF preliminary 1.1fb -1 2 30 GeV | y(  (2S)) | < 0.6 Inclusive total cross-section: Prompt component tot. xsec: preliminary

13. Dec 4th, 2008Alberto Annovi13 Comparison with Run I Run II (1.96TeV) points centered on bin. Run I (1.8TeV) points are on bin centers. B decay points scaled down by 0.1 CDF preliminary 1.1fb -1

14. Dec 4th, 2008Alberto Annovi14 Ratio of cross-sections PRD to be submitted soon Ratio of  (2S) to J/  Ratio of ratio CDF preliminary 1.1fb -1 http://www-cdf.fnal.gov/physics/new/bottom/071018.blessed-psi2S-xsec/ prompt long lived

15. Dec 4th, 2008Alberto Annovi15 Comparisons with NNLO* Theory curve courtesy of P. Artoisenet et al., according to Phys.Rev.Lett.101:152001,2008. [arXiv:0806.3282] see also proceedings for HP2008 submitted to EPJC Yield better described at low-p T. High-p T data (>17 GeV) from this measurement not compatible with theory. Theory progress here is welcome! NNLO* CSM

16. Dec 4th, 2008Alberto Annovi16 search for narrow resonances below the Upsilon mesons

17. Dec 4th, 2008Alberto Annovi17 Why looking for light dimuon resonances?  Low mass sbottom not completely excluded  D.G. Aschman et al., Phys.Rev.Lett.39:124 (1977)  A. M. Boyarski et al., Phys. Rev. Lett. 34, 762 (1975)  CLEO, Phys. Rev. D 63, 051101 (2001)  DELPHI, Phys. Lett. B 444, 491 (1998)  Some models include low mass sbottom  M. Carena et al., Phys.Rev.Lett.86:4463 (2001)  E. L. Berger et al., Phys.Rev.Lett.86:4231 (2001)

18. Dec 4th, 2008Alberto Annovi18 Dimuon spectrum in Run I data G. Apollinari et al. using CDF Run I data Phys.Rev.D72:092003,2005 3.5  excess

19. Dec 4th, 2008Alberto Annovi19 Analysis method  Search for prompt dimuon pairs  look for resonances (epsilon) with detector resolution  Report results as   *BR relative to Y(1S)  Leptonic width of hypotetical sbottomonium  Assumptions for  *BR relative to Y(1S)  Assume  to be unpolarized  Assume p T  to scale with mass w.r.t.  (1S)  i.e. / = m Epsi / m Y(1S)  Assume  to be prompt  Not produced inside a jet, i.e. isolated

20. Dec 4th, 2008Alberto Annovi20 Data sample  630pb -1 from dimuon trigger  June 2006 - January 2007  Trigger selection  1 st central muon p T > 3 GeV, |  | < 0.6  2 nd muon p T > 2 GeV, |  | < 1.1

21. Dec 4th, 2008Alberto Annovi21 Data selection  First reconstruct all dimuon candidates  passing trigger confirmation  Data contains a large contamination of dimuons from  bbbar and ccbar  Require isolation < 4 GeV for both muons  Isolation is sum of all tracks p T in a cone around each muon  Promptness cuts on 3D vertex  Vertex probability > 0.001  L xy /  xy < 3 (L xy w.r.t primary vertex)  Isolation tracks  p T <4GeV

22. Dec 4th, 2008Alberto Annovi22 Dimuon mass spectrum

23. Dec 4th, 2008Alberto Annovi23 Upsi region fit  Fit with  Bkg: 5 th degree polynomial  Sig: Double Gaussians  Fit results  52780 ± 350 Y(1S) events  bkg of 13976 events  9.3 < M < 9.55 GeV  M Y(1S) 9459 ± 1 MeV   M 52 ± 1 MeV

24. Dec 4th, 2008Alberto Annovi24 Resonance search  2 /NDF 66/55 Probability 0.14 Background only: 5 th degree polynomial fit

25. Dec 4th, 2008Alberto Annovi25 Resonance search Add a Gaussian to the fit  We fit in the region 6 to 9.1 GeV  perform 108 fits in steps of 25MeV starting at 6.3 GeV  Peak width is fixed to expectations from simulation: 40 to 48 MeV Probe Gaussian in blue

26. Dec 4th, 2008Alberto Annovi26 Upper limits  90% Bayesian limits  assuming prior probability flat above zero  acceptance correction is  A rel =65.5% of Y(1S) at 6.3 GeV  A rel =97.4% of Y(1S) at 9.0 GeV Where N is number of reconstructed events

27. Dec 4th, 2008Alberto Annovi27 Upper limits 90% CL Red is expected limit. Blue is observed limit. Systematic is 6%  relative acceptance due to Y polarization  resonance line shape modeling The excess in PRD72:092003,2005 was (36±9)*10 -3 at 7.2 GeV

28. Dec 4th, 2008Alberto Annovi28 Upper limits 90% CL Sbottomonium leptonic width http://www-cdf.fnal.gov/physics/new/bottom/080703.blessed-Dimuon_resonance/

29. Dec 4th, 2008Alberto Annovi29 Conclusions   (2S) cross section in Run II  provides data up to 30 GeV for the first time  adds input for quarkonia production understanding  Search for narrow resonances below the Upsilon mesons  no evidence for new signals --> set limits  almost exclude light sbottomonium (6.3 < m < 9 GeV)  not fully excluded within (not shown) theoretical uncertainties

30. Dec 4th, 2008Alberto Annovi30 BACKUP

31. Dec 4th, 2008Alberto Annovi31 Comparison with Run I Run II (1.96TeV) points scaled to 1.8 GeV (-14%) centered on bin. Run I (1.8TeV) points are on bin centers. NRQCD uses a fit to Run I data described in E. Braaten et. Al., hep-ph/0008091 Phys.Rev.D63:094006,2001 CDF preliminary 1.1fb -1