1. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 1 The Y(5S) at CLEO Introduction Bs Reconstruction at the Y(5S) CLEO PRL 96, 022002 (2006) B Reconstruction at the Y(5S) CLEO PRL 96 152001 (2006) Inclusive Ds production at the Y(5S) CLEO PRL 95 261801 (2005) + update CLEO Conf 06-16 Inclusive phi production at the Y(5S) CLEO Conf 06-16 Ian Shipsey Purdue University For the CLEO Collaboration

2. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 2 The Y(5S) discovered by CLEO & CUSB in 1985. massive enough to decay into : Knowledge of B s production at Y(5S) essential for assessing the potential of B s physics at a high luminosity e + e collider. A clean source of B S decays is valuable to interpret New Physics found directly at the LHC. Introduction

3. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 3 Y(5S) Brief History CLEO & CUSB scan in 1985 0.07 fb -1 & 0.12 fb -1 taken on peak CLEO PRL 54 381, 1985 CUSB PRL 54, 377, 1985 CUSB fit to modified potential model Y(5S) Y(6S)? But no conclusive evidence for B s production at Y(5S)

4. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 4 Return to Y(5S) New Data –CLEO III 2003 0.42 fb -1 at 10881 MeV –BELLE 2005 1.86 fb -1 at 10869 MeV (Talk of Drutskoy) –BELLE June 2006 19 fb -1 at 10869 MeV (to be analysed) Analysis differences between Y(5S) and Y(4S): –The ratio of resonance to continuum is larger at the Y(4S) –Same continuum data used for both Y(5S) and Y(4S). But continuum data is almost 300 MeV in CME below Y(5S) and is usually taken at different times. So the continuum subtraction becomes a significant systematic error –Cross sections measured in 1985 have been re-measured –CLEO: (0.301±0.002±0.039) nb –BELLE: (0.305±0.002±0.016) nb –Excellent agreement

5. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 5 An extension of B meson reconstruction technique used at the Y(4S) – MC CLEO Result 1: Observation of the B s @Y(5S) Exclusive reconstruction of the B s CLEO PRL 96, 022002 (2006.) Case 1 Case 2 Case 3

6. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 6 4 events Y(5S)  B s * B s * : 3 B s  J/ , 1 B s  J/ . CLEO Result 1: Observation of the B s @Y(5S)

7. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 7 10 events Y(5S)  Bs * Bs* : Bs  Ds(*)  /  (4 Ds modes)

8. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 8 CLEO Result 2: Ordinary B mesons @ Y(5S) The Y(5S) resonance can decay into a variety of states with ordinary B mesons: 7 possibilities: The center of the signal band for ordinary B mesons The center of the signal band for B s mesons MC Ordinary B decay modes occupy a different region on the ΔE-Mbc plane & have distinct decay modes Use same analysis techniqiue developed for Bs mesons in previous analysis.

9. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 9 With more BB final states (7) Mbc plane is slightly more complicated. Ordinary B Mesons @ Y(5S) Data MC B  D ( * ) (  or  ) & B  J/  K(*)

10. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 10 Ordinary B Mesons @ Y(5S) Use B  D ( * ) (  or  ), B  J/  K(*) Production largest for B*B*, consistent with models –BB/B*B* < 22% @ 90% cl –BB*/B*B* = (24±9±3)% B S * mass –M(B S *)-M(B*)=(87.6±1.6±0.2) MeV –M(B s *)=(5411.7 ± 1.6 ± 0.6) MeV –M(B S *)-M(B S )=(45.7±1.7±0.7) MeV consistent, as expected from Heavy Quark Symmetry with –M(B*)-M(B) =45.78±0.35 MeV 1-D projection beam constrained mass with suitable cuts on  E B*B* BB* BB BB ( * )  BB  CLEO

11. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 11 Ordinary B mesons @ Y(5S) Determine yield from B  D ( * ) (  or  ) & B  J/  K(*) with B invariant mass Total of 53±9 events  =0.177±0.030±0.016 nb, 59% of resonance cross section combine with the sum  = (0.286 ±0.040) nb saturates (within the stats.) Compare to total cross section Translates to f S =0.41±0.10±0.10 Invariant mass

12. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 12 Model Dependent B S Fractions, f S Method use inclusive yield Choose a particle that has very different decay rates from B & B S –Ex: D S measure Model estimate based on quark level diagrams and measured ordinary B decay rates  B(B S →D S X) =(92±11)%

13. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 13 Y(5S) Y(4S) Y(5S) continuum Measurement of f S from Ds Yields -data (Belle) (CLEO) Result 4 x ( |p|/E beam ) Branching Fraction

14. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 14 Measurement of f S Using  Yields Here we need B(B S →  X) Use CLEO-c inclusive yields for B(D o →  X)=(1.0±0.10±0.10)% B(D + →  X)=(1.0±0.10±0.20)% B(D S →  X)=(15.1±2.1±1.5)% Preliminary [hep-ph/0605134 ] From B(B →  X)=(3.5±0.3)%, ascertain that most of  ’s arise from B →D & D S →  Predict that B(B S →  X)=(14.9±2.9)% Result 4

15. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 15 Measurement of f S Using  Yields -data CLEO inclusive  yields, for x<0.5, R 2 <0.25 Y(5S) Y(4S) x ( |p|/E beam ) Branching Fraction

16. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 16 Measurement of B(Y(5S)  B S (*) B S (*) ) Using D S &  Mesons [1] CLEO [PRL 95, 261801 (2005)] [2] CLEO [PRL 96 152001(2006)]  (e+e-  Y(5S)) = (0.301± 0.002 ± 0.039)nb SUMMARY

17. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 17 Summary of f S Measurements Plot: statistical & systematic uncertainties added linearly Average takes into account correlated syst. uncertainties on Y(5S) cross-section model dependencies on Inclusive yields Plot adapted form Stone SuperB Workshop SLAC 6/2006 Combine with Belle

18. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 18 Summary 1 st Observation of the Bs at the Y(5S) and determination of the composition of BsBs final states. Bs*Bs* dominates 1 st determination of the composition of ordinary BB final states at Y(5S). B*B*:BB*:BB ~ 3:1:<1, –Upper limits for BB,B (*) B (*)  and BB  Bs*Bs BsBs. Both Bs & B compositions consistent with predictions M(B s *)=(5411.7 ± 1.6 ± 0.6) MeV world ’ best measurement. M1 Mass splitting: M(B S *) - M(B S ) = (45.7 ± 1.7 ± 0.7) MeV as expected by HQS: Inclusive yields of Ds and phi mesons measured for the first time  Bottom line: between about ¼ (0.07 nb) & 1/3 (0.11 nb) of Y(5S) decays to B S ( * ) B S ( * ) These estimates are model dependent and indicate that an extended Y(5S) run at a B factory would be fruitful. Belle results from 1.8/fb run are in broad accord with the above results

19. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 19

20. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 20 Additional Slides

21. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 21 Y5S Y4S Result 3

22. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 22

23. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 23 Comparisons with Models UQM predicts  R~0.4, f S =38%, B S *B S * large QHM predicts  R~0.7, f S =21%, B S *B S * large Other models: –Martin & Ng, Z Phys. C 40, 133 (1988) –Byers [hep- ph/9412292 Unitarized Quark Model..................... Y(5S) Quark Hybrid Model Y(5S)

24. I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 24 Model of D S Production Must assume knowledge of B(B S →D S X) Account for fragmentation that reduces D S rate from B S, CLEO & BELLE use same model B(B S →D S X) =(92±11)%