1. Intae Yu Sungkyunkwan University, Suwon, Korea Tevatron B Physics workshop @ KISTI, August 24 th, 2009 B Physics Analysis and Plan at SKKU

2. Tevatron B Physics Workshop @ KISTI, August 24th 2009 2 SKKU CDF group: Brief Review  Current Group: 1 faculty, 1+? graduate students  Past Research Activities  TOF PMT Test and Calibration CDF Note 5386  COT Tracking Efficiency CDF Note 6394, 6594  B s Lifetime CDF Note 6195, 6395  B c Meson Lifetime and Cross Section CDF Note 7518, 7926, 7985: PRL 97, 012002 (2006)  Cabibbo Suppressed Decays of B + Meson CDF Note 6967, 7763, 8236, PRD 79, 112003 (2009)

3. Tevatron B Physics Workshop @ KISTI, August 24th 2009 3 쳑Current Research Activity  Exclusive Decays of B Mesons to X(3872)  Provides important clues to structure of X(3872)  Analyzed 1.4 fb -1 of data  Present preliminary results at a CDF internal meeting  Decay modes: B + →X(3872)K + : Observed. Consistent with Belle and Babar Results B 0 →X(3872)K 0 : Analysis is in progress

4. Tevatron B Physics Workshop @ KISTI, August 24th 2009 4 Physics Motivation X(3872) was first discovered by Belle in charged B meson decay and later confirmed by Babar in the same mode (B + → X(3872)K +, X(3872) →J/ψπ + π - ). Also observed at CDF and D0 in X(3872) →J/ψπ + π - decay We reconstruct B→X(3872) K exclusive decays and measure the branching fractions and masses of X(3872) in each mode The result of this analysis provides an important information to check various interpretations for X(3872) - molecule model, tetraquark model, charmonium,…. Belle and Babar measured the mass difference and relative branching ratio of B 0 →X(3872)K 0 to B + →X(3872)K + in 2008 and their results show some inconsistency 0.18±0.89±0.26 MeV/c 2 0.82±0.22±0.05 (Belle) 2.7±1.6±0.4 MeV/c 2 0.41±0.24±0.05 (Babar) < 3.2 MeV/c 2 (90%CL) (CDF)

5. Tevatron B Physics Workshop @ KISTI, August 24th 2009 5 Decay Topology and Reference Mode Choose B→ψ(2S)K, ψ(2S)→J/ψπ + π - decay as the reference mode –Same final states (J/ψπ + π - K) –Similar kinematics (ΔM(ψ(2S), X) ~ 185 MeV/c 2 ) Enough number of events in both B + →ψ(2S)K + and B 0 →ψ(2S)K 0 decays [Decay topology of B + mode][Decay topology of B 0 mode]

6. Tevatron B Physics Workshop @ KISTI, August 24th 2009 6 Reconstruction of Clear peak of B + meson observed –Unbinned fit with Gaussian+2nd order polynomial (rhs) –Yields 49.7 ± 12.3 signals –Statistical significance of

7. Tevatron B Physics Workshop @ KISTI, August 24th 2009 7 Relative Branching ratio Relative branching ratio of B to XK to B to ψ(2S)K can be measured : – : # of candidates in X(3872) mode – : # of candidates in ψ(2S) mode – : Overall signal efficiency in X(3872) mode – : Overall signal efficiency in ψ(2S) mode Use same cuts to ψ(2s) mode (to minimize systematic) –Except the dipion mass cut M ππ > 0.5 GeV/c 2 for X(3872), 0.31 < M ππ <0.61 GeV/c 2 for ψ(2S)

8. Tevatron B Physics Workshop @ KISTI, August 24th 2009 8 Fit with single gaussian and 2 nd order polynomial Observed Number of Signals

9. Tevatron B Physics Workshop @ KISTI, August 24th 2009 9 Relative signal efficiency & Relative Branching Fraction Generated 4,928,804 events in both of modes B P T > 5GeV/c & |η| <1.3 After applying final cuts, –15,634 candidates remain in ψ(2S) mode –19,825 candidates remain in X(3872) mode The relative efficiency was measured to be :  Combining the above, we get the relative branching fraction as follows:

10. Tevatron B Physics Workshop @ KISTI, August 24th 2009 10 Systematic Most of the systematic errors cancel out Counting number of signals – Fitting –Possible bias/errors in fitter Check pull distribution –Fitting range Observe effect of variation of fitting range Efficiency measurement –MC generator : assumption of dipion mass spectrum Observe changes of result with measured dipion mass histogram

11. Tevatron B Physics Workshop @ KISTI, August 24th 2009 11 Systematics : Summary SourceUncertainty Fitternegligible Fitting Range±0.6% dipion mass spectrum7.5%(neg. only) Total+0.6% -7.5%  Preliminary Result:

12. Tevatron B Physics Workshop @ KISTI, August 24th 2009 Selection for B 0 mode K s has long decay length : –No SVX hit requirements for pion tracks from K s –Refit tracks setting setInnerRadius() for material integration Follow selections in K + modes –Similar kinematics –Inherit cut sets from K + modes –K s selection Lxy > 0.1 3σ mass range 12 VariableSelection P T (B 0 )> 6.5 GeV/c P T (K s 0 )> 2 GeV/c Lxy(K s 0 )> 0.1cm L xy (B 0 )/σL xy (B 0 )> 3 M ππ X : M ππ > 0.5 GeV/c2 Ψ (2S) : 0.31 < M ππ < 0.61 GeV/c 2

13. Tevatron B Physics Workshop @ KISTI, August 24th 2009 MC generation & Efficiency calculation Same algorithm used in K + mode (phase space decay with dipion mass spectrum) –S-wave parameterization forψ(2S) decay –Non-relativistic BW for X(3872) decay # of MC events after final cuts –ψ(2S) : 4298 passed in 2,976,709 events –X (3872): 5306 passed in 2,999,816 events Relative efficiency 13 (stat. only)

14. Tevatron B Physics Workshop @ KISTI, August 24th 2009 B 0 →Ψ(2S)K 0 s Mass fit in B 0 →Ψ(2S)K 0 s mode –Gaussian + 1 st order polynomial –73.2 signals observed 14 gFrac=0.389±0.042 gMean=5.278±0.001 sigma=0.096±0.001 slope=-6.071±1.908 nSig=73.18 ± 7.908

15. Tevatron B Physics Workshop @ KISTI, August 24th 2009 In B 0 mode, we plan to measure R R = Br(B 0 →X(3872)K 0 )/Br(B + →X(3872)K + ) R < 0.1 in molecule models R ~ 1 in the tetraquark model To check the MC relative efficiency between B 0 and B + in X mode, we measure the relative branching ratio of two reference modes using MC efficiencies and compared it with PDG value. PDG average is : 0.331 ± 0.037 Assume σ(B 0 ) = σ(B + ) Preliminary analysis of B 0 → X(3872)K 0 s is in progress 15 Efficiency Check

16. Tevatron B Physics Workshop @ KISTI, August 24th 2009 16 Summary Observation of  Yield : 49.7 ± 12.3  Statistical significance : Ratio of Branching Fractions in B + modes Study of B 0 →X(3872)K 0 s  Reference mode B 0 →ψ(2S)K 0 s is reconstructed  Analysis of B 0 →X(3872)K 0 s mode is in progress

17. Tevatron B Physics Workshop @ KISTI, August 24th 2009 17 Prospects  Exclusive Decays of B Mesons to X(3872)  Process more data (currently 5.6 fb -1 )  Systematic uncertainties to be investigated  B + →X(3872)K +, B 0 →X(3872)K 0 : branching ratio and mass  B 0 →X(3872) K + π - mode : in preparation (reported by Belle)  Get blessed asap and go to publication

18. Tevatron B Physics Workshop @ KISTI, August 24th 2009 18 Research Interests  Search for Z(4430) + Discovered at Belle in the decay Z(4430) + → ψ(2S) π + Not observed at Babar (need independent confirmation)  Search for Exotic States in the Upsilon system Unusually large partial width Υ(5S)→Υ(1S) π + π -, Υ(5S)→Υ(2S) π + π - (Belle) Possible exotic state Z’ → Υ(1S) π +, Υ(2S) π+ corresponding to Z(4430) (M. Karliner, H.J. Lipkin, arXiv:0802.0649 )  New Bs Decays Bs → J/ψKs Bs → X(3872)φ→ J/ψπ + π - φ Welcome suggestions and discussions

19. Tevatron B Physics Workshop @ KISTI, August 24th 2009 http://lpnhe-cdf.in2p3.fr/cdf_Fr_Korea/ LPNHE

20. Tevatron B Physics Workshop @ KISTI, August 24th 2009 20 FKPPL Workshop FKPPL (France-Korea Particle Physics Laboratory) KISTI-LPNHE Joint Project FKPPL-CDF Workshop (June 29 ~ July 1 @ Paris) probes the possibility of Korea-France Collaboration 1 st Day : B Physics Session CP Violation in Bs system New Bs decays