A. Drutskoy, University of Cincinnati B physics at  (5S) July 24 – 26, 2006, Moscow, Russia. on the Future of Heavy Flavor Physics ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy ITEP Meeting

Outline Recent Belle measurements at the Y(5S). Future searches for BSM using B s decays at Y(5S). Introduction. Conclusion. ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

CLEO PRL 54, 381 (1985)  (5S) Introduction e + e - -> Y(5S) -> BB, B * B, B * B *, BB , BB , B s B s, B s * B s, B s * B s * where B * -> B  and B s * -> B s  Asymmetric energy e + e - colliders (B Factories) running at Y(4S) : Belle and BaBar _ ______ 1985: CESR (CLEO,CUSB) ~116 pb -1 at Y(5S) 2003: CESR (CLEO III) ~0.42 fb -1 at Y(5S) __ B s rate is ~10-20% => high lumi e + e - collider at the Y(5S) -> B s factory. 2005: Belle, KEKB ~ 1.86 fb -1 at Y(5S) CLEO PRL 54, 381 (1985)  ( 5S )  (4S) 2006, June 9-31: Belle, KEKB ~21.7 fb -1 at Y(5S) e + e - ->Y(4S) -> BB, where B is B + or B 0 meson M(Y(5S)) =  8 MeV/c 2 (PDG)  (Y(5S)) = 110  13 MeV/c 2 (PDG) ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Belle First Y(5S) runs at the KEKB e + e - collider 3.5 GeV e + 8 GeV e - Electron and positron beam energies were increased by 2.7% (same Lorentz boost  = 0.425) to move from Y(4S) to Y(5S). No modifications are required for Belle detector, trigger system or software to move from Y(4S) to Y(5S). Integrated luminosity of ~1.86 fb -1 at 2005 and ~21.6 fb -1 at 2006 was taken by Belle detector at Y(5S). The same luminosity per day can be taken at Y(4S) and Y(5S). Very smooth running ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Integrated luminosity reached 600 fb -1 on May 31 st. Belle Babar ~630fb -1 May-31 st Belle integrated luminosity at Y(4S) ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Inclusive analyses : Y(5S) -> D s X, Y(5S) -> D 0 X Y(5S) D s ->   ± 100 ev After continuum subtraction and efficiency correction: Bf (Y(5S) -> D s X) 2 = (23.6 ± 1.2 ± 3.6) % => points:5S hist: cont D 0 -> K -  + D s ->   + points:5S hist: cont P/P max <0.5 f s = N(B s ( * ) B s ( * ) ) / N(bb) Bf (Y(5S) -> D 0 X) 2 = (53.8 ± 2.0 ± 3.4) % = (18.0 ± 1.3 ± 3.2 )% N bb (5S) = 561,000 ± 3,000 ± 29,000 events L = 1.86 fb -1 N(B s ) / fb -1 = 108,000 ± 21,000 events ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Signature of fully reconstructed exclusive B s decays B s B s, B s *B s, B s *B s * Figures (MC simulation) are shown for the decay mode B s -> D s -  + with D s - ->   -. M bc = E* beam 2 – P* B 2, The signals for B s B s, B s *B s and B s * B s * can be separated well. e + e - -> Y(5S) -> B s B s, B s *B s, B s *B s *, where B s * -> B s  M bc vs  E  E = E* B – E* beam Reconstruction : B s energy and momentum, photon from B s * is not reconstructed. Two variables calculated: MC Zoom M bc vs  E ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Exclusive B s -> D s ( * )+  - /  - and B s -> J/  /  decays B s -> D s +  - B s -> D s * +  - B s -> D s ( * )+  - B s -> J/  7 evnts in B s * B s *3 evnts in B s * B s *9 evnts in B s * B s *4 evnts in B s * B s * N(B s *B s *) / N(B s ( * ) B s ( * ) ) = (94± 6 9 )% Potential models predict B s * B s * dominance over B s *B s and B s B s channels, but not so strong <M BC < 5.429GeV/c 2 B s * N ev =20.0 ± 4.8 Conclusions: 1. Belle can take ~30 fb -1 per month ( x 2 soon). 2. Number of produced B s at Y(5S) is ~10 5 /fb B s *B s * channel dominates over all B s ( * ) B s ( * ). 4. Backgrnds in exclusive modes are not large. Data at Y(5S), 1.86 fb -1 ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

 s /  s measurement from Bf (B s -> D s +( * ) D s - ( * ) ) M Bs = (M H + M L )/ 2  s = (  H +  L )/ 2 i d d t ( ) BsBs BsBs = ( M – / 2  ) i ( ) BsBs BsBs - Schrodinger equation Matrices M and  are t-dependent, Hermitian 2x2 matrices Assuming CPT: M 11 = M 22  11 =  22 | B H,L (t) > = exp( - ( i M H,L +  H,L / 2)t ) | B H,L > BSM  s = arg (- M 12 /  12 ) 2  s =  s  s = 2 |  12 | cos 2  s SM:  s =arg(-V ts V tb */ V cs / V cb *) =O( 2 ) - no CP-violation in mixing  m s = M H – M L  =  L -  H >0 in SM “ ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

 s = 2 |  12 | cos  s  s SM =  CP s = 2 |  12 | To prove this formula experimentally : a) Contribution of B s -> D s +( * ) D s - ( * ) n  is small b) Most of B s -> D s + D s - * and B s -> D s + * D s - * states are CP- even. Since  CP s is unaffected by NP, NP effects will decrease  s. Assuming corrections are small (~5-7%), Bf measurement will provide information about  CP s or |  12 |. B s ->D s ( * ) + D s ( * ) - decays have CP- even final states with largest BF’s of ~ (1-3)% each, saturating  s /  s.  CP s =   (CP=+) –   (CP= –)  s /  s measurement from Bf (B s -> D s +( * ) D s - ( * ) )  CP s ss ~ ~ Bf(B s ->D s ( * ) + D s ( * ) - ) 1- Bf(B s ->D s ( * ) + D s ( * ) - ) / 2 ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

D s + ->  +, K* 0 K +, K s K + Eff(B s ->D s + D s - ) ~ 2x10 -4 Eff(B s ->D s * + D s - ) ~1x10 -4  CP s ss ~ Bf(B s ->D s ( * ) + D s ( * ) - ) 1- Bf(B s ->D s ( * ) + D s ( * ) - ) / 2 Expected with 100 fb -1 at Y(5S): => Accuracy of Bf (B s ->D s ( * ) + D s ( * ) - ) has to be ~15%. should be compared with direct  s /  s measurement to test SM. <= ~ B s -> D s + D s - B s -> D s * + D s - B s -> D s * + D s * - Eff(B s ->D s * + D s * - ) ~5x10 -5 N ~ 10 7 x 2x10 -4 x ~ 20 ev N ~ 10 7 x x 2x10 -2 ~ ev N ~ 10 7 x 5x10 -5 x 3x10 -2 ~ 15 ev  s /  s lifetime difference can be measured directly with high accuracy at Y(5S) and also at Tevatron and LHC experiments.  s /  s measurement from Bf (B s -> D s +( * ) D s - ( * ) ) Y(5S), 1.86 fb -1 ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Semileptonic B s decays At the Y(5S) we can measure precisely semileptonic decays: Bf (B s ->X + l - ) Bf (B s ->D s + l - ) Bf (B s ->D s * + l - ) Motivations: 1.  (B 0 ) >  (B s )  difference (in contrast with theory). 2. Measured B 0 semileptonic Bf is a bit lower than theoretical prediction. These Bf’s have to be compared with corresponding B meson Bf’s. This comparison provides important test of SU(3) symmetry and quark-qluon duality. Accuracy is expected to be ~5% with 100 fb -1 at Y(5S) Difficult to measure in hadron-hadron colliders. ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

90% CL UL with 1.86 fb -1 : Bf (B s ->  ) < 0.56 x PDG limit : Bf (B s ->  ) < 1.48 x MC B s ->  Exclusive B s ->   decay Natural mode to search for BSM effects, many theoretical papers devoted to this decay. Expected UL with 100 fb -1 : Bf (B s ->  ) < 1. x SM : Bf (B s ->  ) = ( ) x BSM can increase Bf up to two orders of magnitude fb -1 ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Exclusive B s ->   decay Many “conventional” BSM models can be better constrained by B -> K*  and B->s  processes, however not all. In some BSM models B s ->  provides the best limit, in particular in 4-generation model (V Ts ) and R- parity violating SUSY ( x M(  )). V Tb V Ts hep-ph/ (Huang et al) : limits on four-generation matrix elements V Tb and V Ts were obtained from B decays. Bf(B s ->  ) can increase up to one order of magnitude under specific conditions. Decay B->  is not affected. b s _ _    hep-ph/ (Gernintern et al): within R-parity violation SUSY, diagram with sneutrino will increase Bf(B s ->  ) up to one order of magnitude. ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Exclusive B s -> K + K -, B s -> K -  + and B s ->  decays Direct CP-violation => non-zero charge asymmetry parameter A = (Bf (+) – Bf (-) ) / (Bf (+) – Bf (-) ). Expected number of events with 100 fb -1 : B s -> K + K - : ~40 events ; B s -> K -  + : ~6 events. Larger statistics is required to observe direct CP-violation on the level of 10%. B s ->  Partner of B -> K*  penguin decay. Bf’s have to be compared. Estimated number of events with 100 fb -1 : ~20 ev. New Physics can contribute in penguin decay loops. ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Conclusions B s studies at e+ e- colliders running at Y(5S) have many advantages comparing with hadron-hadron colliders: high efficiency of photon reconstruction; 100% trigger efficiency; good K/  PID. B s decays with branching fractions down to can be studied with statistics of ~100 fb -1 at e+e- colliders running at Y(5S). Many important SM tests can be done with statistics of the order of ( ) fb -1. ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Background slides ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

hadronic events at  (5S) u,d,s,c continuum bb events B s * B s B s B s * B s * channel B s events b continuum  5S) events Hadronic event classification CLEO PRL 54, 381 (1985)  (5S) B 0, B + events N(bb events) = N(hadr, 5S) - N(udsc, 5S) f s = N(B s ( * ) B s ( * ) ) / N(bb) ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Number of bb events, number of B s events How to determine f s = N(B s ( * ) B s ( * ) ) / N(bb)? x 2. Bf (B -> D s X) is well measured at the Y(4S). 1. Bf (B s -> D s X) can be predicted theoretically, tree diagrams, large. bb at Y(5S) B B s _ Y(5S) :Lumi = ± (stat) fb -1 N bb (5S) = 561,000 ± 3,000 ± 29,000 events Cont (below 4S) : ± (stat) fb -1 _ => 5% uncertainty ( from luminosity ratio) Bf (B -> D s X)Bf (Y(5S) -> D s X) / 2Bf (B s -> D s X) = f s + (1- f s ) x ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Feasibility of B s lifetime measurement with same sign leptons Lifetime can be measured using two fast same sign lepton tracks and beam profile. To remove secondary D meson semileptonic decays: P( l )>1.4 GeV. ++  z =  c  t ++ Y(5S) BsBs BsBs Beam profile Z beam ~ 3 mm;  z ~ mm. Y(5S) : B s ( l + ) B s ( l + ) / B s ( l + ) B s ( l - ) = 100% Y(5S) : B( l + ) B( l + ) / B( l + ) B( l - ) ~ 10% ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy

Comparison with Fermilab B s studies. Running at Y(5S) is a new tool to study B s physics. First Belle results are very promising. Collider exists => relatively low price. There are several topics, where Y(5) running has advantages comparing with CDF and D0: 1) Model independent branching fraction measurements. 2) Measurement of decay modes with ,  0 and  in final state (D s +  - ). 3) Measurement of multiparticle final states (like D s + D s - ). 4) Inclusive branching fraction measurements (semileptonic B s ). 5) Partial reconstruction (Bf (D s + l - ) using “missing- mass” method). There are also disadvantages: 1) We have to choose between running at Y(4S) or Y(5S). 2) Number of B s is smaller than in Fermilab experiments. 3) Vertex resolution is not good enough to measure B s mixing. ITEP Meeting B physics at Y(5S), July , 2006, Moscow, Russia A. Drutskoy