Bs physics at Y(5S) in Belle experiment AAAA A. Drutskoy University of Cincinnati Bs physics at Y(5S) in Belle experiment SLAC Experimental Seminar January 17, 2006, SLAC. Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy AAAA Outline Introduction. Data taking. Number of bb events at Y(5S) dataset. Inclusive production of J/Y, D0 and Ds at Y(5S). Exclusive decays Bs-> J/Y f (/h) and Bs-> Ds+(*) p- (/r-). Search for rare Bs decays. Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy AAAA Introduction CLEO PRL 54, 381 (1985) (5S) 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) _ e+ e- ->Y(4S) -> BB, where B is B+ or B0 meson _ _ _ _ _ _ _ _ e+ e- -> Y(5S) -> BB, B*B, B*B*, BBp, BBpp, BsBs, Bs*Bs, Bs*Bs* where B* -> B g and Bs* -> Bs g _ _ _ B0 = s b , B0 = s b s s Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Masses, widths, lifetimes, CM momenta AAAA Masses, widths, lifetimes, CM momenta Particle Mass, MeV/c2 Width, DM, ct, mm Pcm(BB), MeV/c Y(4S) 10580.0  3.5 20  2  4 Y(5S) 10865  8 110  13 B+ 5279.0  0.5 502 1282 B0 5279.4  0.5 462 1281 B* 5325.0  0.6 45.8  0.4 1075 Bs 5365.5  1.3 438 851 Bs* 5416.6  3.5 51  4 415 Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy AAAA Electron and positron beam energies have to be increased by 2.7% (same Lorentz boost bg = 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). Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Engineering run at Y(5S) 3 days of engineering run at Y(5S) : June 21 – June 23. Plan for 3 day engineering runs: 1. Energy scan: five points with ~30 pb-1 at each point: 10825, 10845, 10865, 10885 and 10905 MeV. 2. Data taking at Y(5S) peak; to collect integral lumi ~2 fb-1 . Results: Y(5S) peak position ECM=10869 MeV was chosen from energy scan. Integrated luminosity of ~1.86 fb-1 (ECL lumi) was taken !!! Maximum luminosity ~13.9 /nb/sec, almost 100% of Y(4S) specific luminosity (taking into account smaller currents). Belle can take 1 fb-1 per day at Y(5S) or even more. Very smooth running, all goals are reached. Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy

Hadronic event classification hadronic events at U(5S) AAAA Hadronic event classification hadronic events at U(5S) U(5S) events u,d,s,c continuum b continuum bb events CLEO PRL 54, 381 (1985) (5S) Bs events B0, B+ events Bs* Bs* channel Bs* Bs Bs Bs Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy AAAA Number of Bs in dataset To calculate any exclusive branching fraction we must know the full number of Bs* Bs* events. To calculate any inclusive branching fraction we must know the full number of Bs mesons. To obtain the full number of initial Bs* Bs* events in our data sample we should go through steps: 1. Obtain the number of hadronic events in Y(5S) dataset. 2. Subtract u,d,s,c continuum using continuum data below Y(4S) with luminosity scale factor. 3. Calculate the ratio N(Bs(*)Bs(*)) / N(bb) using inclusive Ds and D0 spectra. 4. Calculate the ratio N(Bs*Bs*)/ N(Bs(*)Bs(*)) using reconstructed exclusive events. Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy AAAA Number of bb events. Ncont(5S) = Ncont(E=10.519)* L(5S) / L(cont) * (Econt/E5S)2 (e5S/ econt) Y(5S) : Lumi = 1.857 ± 0.001 (stat) fb-1 Cont : Lumi = 3.670 ± 0.001 (stat) fb-1 s ~ 1/Ecm 2 (1.857/3.67)*(10.5189/10.869)2 = 0.4740± 0.0019 e5S/ econt = 1.007 ± 0.003 Nbb(5S) = 561,000 ± 3,000 ± 29,000 R = s(hadrons) / s(mm) Nbb(5S) / fb-1 = 302,000 ±15,000 CLEO : 0.42 fb-1 Nbb(5S)/ fb-1 = 310,000 ± 52,000 Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Luminosity ratio L (5S) / L (continuum). AAAA Luminosity ratio L (5S) / L (continuum). We obtained luminosity ratio: L (5S) / L (cont) = 0.4740 ± 0.0019 Luminosity ratio can be checked using the ratio of normalized momentum distributions of fastest charged track, fastest K0 and D0 mesons. Using MC simulation CLEO obtained (0.6 ± 1.1)% correction for new channels opening. That correction was applied to these numbers. 0.471 ± 0.005 0.471 ± 0.005 0.477 ± 0.005 => Good agreement within errors with energy corrected luminosity ratio. Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy AAAA Inclusive analyses : selections Particle ID: p/K : standard ID(K/p) J/Y -> m+ m- : Standard Muon ID D0 -> K+ p- : no cuts Ds -> fp: | M(f) – M(K+K-) | < 12 MeV/c2 ~3s |cos(qheli) (Ds)| > 0.25 for fp+ No continuum suppression cuts. Ratio of Bs(*) Bs(*) pair number to all bb pair number fs = N(Bs(*) Bs(*)) / N(bb) can be obtained from: Bf (Y(5S) -> Ds X) / 2 = fs Bf (Bs -> Ds X) + (1- fs) Bf (B -> Ds X) x x Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy AAAA Inclusive analysis : Y(5S) -> Ds X Theory : hep- ex/0508047 CLEO Y(5S) P/Pmax< 1 Bf (Bs -> Ds X) = (92 ± 11) % PDG : Bf (Ds-> f p+)=(3.6 ± 0.9)% Babar : Bf(Ds-> f p+)=(4.8 ± 0.6)% Ds-> f p+ Sum: Bf(Ds-> f p+) = (4.4 ± 0.5)% 3775 ± 100 ev CLEO : Bf (B -> Ds X) = ( 9.0 ± 0.3 ±1.4 )% Babar : Bf (B -> Ds X) = ( 8.94 ± 0.16 ± 1.12 )% After continuum subtraction and efficiency correction: Bf (Y(5S) -> Ds X) 2 = (22.6 ± 1.2 ± 2.8) % CLEO measured: Bf (Y(5S) -> Ds X) / 2 = (22.35 ± 2.1 ± 4.95)% => fs = (16.4 ± 1.4 ± 4.1 )% Syst. err. dominates by Bf(Ds->fp+) Using Ds mesons CLEO measured fs = (16.0 ± 2.6 ± 5.8 )% Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy AAAA Inclusive analysis : Y(5S) -> D0 X Theory : hep- ex/0508047 CLEO Y(5S) Bf (Bs -> D0 X) = (8 ± 7) % PDG: D0 -> K- p+ Bf (B -> D0 X) = (63.7 ± 3.0) % 55009 ± 510 ev Bf (D0 -> K- p+) = (3.81 ± 0.09 ) % P/Pmax< 1 After continuum subtraction and efficiency correction: Bf (Y(5S) -> D0 X) 2 = (53.3 ± 2.0 ± 2.9) % Then we obtain ratio fs = N(Bs(*) Bs(*)) / N(bb) : fs = (18.7 ± 3.6 ± 6.7 )% Syst. error dominates by N(bb). Using Ds mesons CLEO measured fs = (16.0 ± 2.6 ± 5.8 )% Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy AAAA Inclusive analysis : Y(5S) -> J/Y X Theory : Bf(Bs-> J/Y X) P/Pmax<0.5 Y(5S) = 1.00 ± 0.10 Bf(B -> J/Y X) 446±28 ev m+m- PDG: Bf (B -> J/Y X) = (1.094 ± 0.032) % Bf (J/Y -> m+ m- ) = (5.88 ± 0.10 ) % After continuum subtraction and efficiency correction: Bf (Y(5S) -> J/Y X) 2 = (1.068 ± 0.086 ± 0.057) % Good agreement with expectations => bb number is correct Assuming approximately 17% Bs(*)Bs(*) production over bb : Bf ( Bs -> J/Y X) = ( 0.94 ± 0.51 ± 0.37 ) % Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Exclusive analysis: signature of fully reconstructed Bs decays AAAA Exclusive analysis: signature of fully reconstructed Bs decays BsBs , Bs*Bs , Bs*Bs* Mbc vs DE Mbc = E*beam2 – P*B2 e+ e- -> Y(5S) -> BB, B*B, B*B*, BsBs, Bs*Bs, Bs*Bs* where B* -> B g and Bs* -> Bs g Detailed MC event simulation and reconstruction with Belle detector was performed. Figures are shown for decay mode Bs -> Ds- p+ with Ds- -> f p- . Bs signal can be well separated for BsBs, Bs*Bs and Bs* Bs* final states. Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Exclusive analyses: selections Particle ID: K/p: standard ID(K/p) ; standard lepton ID Masses: p0 –> gg 3s KS –> p+ p- 3s K*0 –> K+ p- h –> gg 2.5s r+ –> p+ p0 , P(g) >150 MeV/c f – > K+K- 3s – 30 < M(m+m-) – M(J/y) < 30 MeV/c2 3s – 100 < M(e+e-) – M(J/y) < 30 MeV/c2 Ds+ -> fp+ , K*0 K+, Ks K+ 3s Ds*+ -> Ds+ g : M(Dsg)- M(D*s), 2s , P(g)>50 MeV/c Continuum suppression: Angle between Bs thrusts: |cosq| < 0.8 for Ds(*)+ p- ; |cosq| < 0.9 for J/Y ; |cosq| < 0.7 for Ds(*)+ r- ; |cosq| < 0.6 for K*0 K+ modes ; Fox2<0.3 for Ds(*)+ p-/ r-; Fox2<0.4 for J/y modes Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy

Exclusive Bs -> Ds(*)+ p- decays Bs -> Ds+ p- Bs -> Ds*+ p- AAAA Exclusive Bs -> Ds(*)+ p- decays Bs -> Ds+ p- Bs -> Ds*+ p- BsBs , Bs*Bs , Bs*Bs* MC 9 events in Bs* Bs* 4 events in Bs* Bs* Ds+ -> f p+ , Ds+ -> K*0 K+, Ds+ -> Ks K+ Clear signal at Bs* Bs* channel ; no signals in Bs* Bs and BsBs channels. Taking full number of Bs from inclusive analysis: Bf(Bs -> Ds+ p- ) = (0.65 ± 0.21 ± 0.19)% CDF measured Bf ratio, taking Bf(B0->D+p-) from PDG: (0.40 ± 0.06 ± 0.13)% Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Exclusive Bs -> Ds(*)+ r- and Bs -> J/y f/h decays AAAA Exclusive Bs -> Ds(*)+ r- and Bs -> J/y f/h decays Bs -> Ds(*)+ r- Bs -> J/y f/h 7 events in Bs* Bs* 3 events in Bs* Bs* Ds+->f p+ ,Ds+->K*0 K+,Ds+->KsK+ Bs -> J/y f, Bs -> J/y h(gg) Clear signal at Bs* Bs* channel ; signals in Bs* Bs and BsBs channels are not seen. Bs* Bs* channel dominance was also observed by CLEO (next slide). We can combine all shown channels to obtain quantitative Bs(*) parameters. Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

H. Vogel, CLEO, FPCP 2004 (obsolete), Korea, exclusive Bs decays AAAA Exclusive Bs Signals at the (5S) BsJ/' , J/+e+e-  K+K  Ebeam – Ecandidate (GeV) Mbc (Bs candidate) (GeV) BsDs(*) Ds*Ds DsK+K0 K+K*0  Ebeam – Ecandidate (GeV) Mbc (Bs candidate) (GeV) Preliminary Nsignal = 4, Nbkg  0.1 Nsignal = 8, Nbkg  1 (5S) decay to Bs(*)Bs(*) is dominated by the Bs*Bs* mode! H. Vogel, CLEO, FPCP 2004 (obsolete), Korea, exclusive Bs decays Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy - 13 - A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

DE distributions, sum of all Bs decay modes AAAA DE distributions, sum of all Bs decay modes 5.408< MBC<5.429 GeV/c2 5.384< MBC<5.405GeV/c2 5.36< MBC<5.38GeV/c2 Bs* Bs* Bs* Bs Bs Bs Nev=20.0 ± 4.8 6.7 s Small signal, Nev= 1.3 ± 2.0 (6± 96)% Decay U(5S) -> Bs* Bs* , with Bs* -> Bs g. Potential models predict Bs* Bs* dominance over Bs*Bs and BsBs channels, but not so strong. DE peak = Ecm(accel.)/2 – Ecm(real)/2 – E(g) DE peak = – 47.6 ± 2.6 MeV Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

MBC distribution, sum of all Bs decay modes AAAA MBC distribution, sum of all Bs decay modes - 0.08<DE<- 0.02 MeV - 0.08<DE<- 0.02 MeV Bs* Bs* Bs* Bs* Mbc = (E*B+ DEpeak)2 – P*B2 Mbc = E*B2 – P*B2 M (Bs) = 5370 ± 1 ± 3 MeV/c2 Ecm = 10869 MeV ; E*B = Ecm/2 M (Bs*) = 5418 ± 1 ± (acc. err) MeV/c2 PDG: M (Bs) = 5369.6 ± 2.4 MeV/c2 CDF: M (Bs) = 5366.0 ± 0.8 MeV/c2 Photon momentum is neglected => does not change Bs* mass position, only smearing. Photon energy smearing does not change Bs mass position Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

hadronic events at Y(5S) AAAA Number of Bs in dataset hadronic events at Y(5S) Lumi = 1.857 fb-1 bb continuum included bb events N ev = 561,000 ± 3,000 ± 29,000 fs = (16.4 ± 1.4 ± 4.1 )% Bs events N ev = 92,000 ± 8,000 ± 23,000 f(Bs*Bs*) = (94 ± 69)% Bs* Bs* channel N ev = 86,500 ± 7,500 ± 22,500 Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Exclusive Bs -> K+ K- and Bs -> f g decays AAAA Exclusive Bs -> K+ K- and Bs -> f g decays Bs -> K+ K- Bs -> f g MC Fox2 < 0.3, Fox2 < 0.4, |cos q| < 0.5 |cos q| < 0.8 K- : tight ID(K/p), Bgr. ~ 0.15 ev. Est. sign.~ 0.4 ev. Bgr. ~ 0.14 ev. Est. sign.~ 0.7 ev. Partner of B -> K+ p- penguin decay Partner of B -> K* g penguin decay Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

CDF: Bs-> h+ h’- decays fs Bf( Bs -> K+ K-) Unbinned likelihood fit. = 0.50 ± 0.08 ± 0.07 fd Bf( B0 -> K+ p-) fs Bf( Bs -> K+ p-) < 0.11 (90%CL) fd Bf( B0 -> K+ p-) Bf( Bs -> p+ p-) < 0.10 (90%CL) Bf( Bs -> K+ K-) No absolute branching fractions. Statistical separation of final states. Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy

Exclusive Bs -> Ds(*)+ Ds(*)- decays Angle between B thrusts: AAAA Exclusive Bs -> Ds(*)+ Ds(*)- decays Bs-> Ds+ Ds- Bf(Bs->Ds+ Ds- ) < 7.1% at 90% CL Bs-> Ds*+ Ds- Bf(Bs->Ds*+ Ds- ) < 12.7% at 90% CL Bs-> Ds+ Ds*- Bf(Bs->Ds*+ Ds*- ) < 27.3% at 90% CL Bs-> Ds*+ Ds*- Expected (2 fb-1): ~ 0.5 events in each mode. Expected with 30 fb-1: Bf (Bs->Ds(*)+ Ds(*)- ) = (12 ± 5 )% Ds+ -> fp+ , K*0 K+, Ks K+ Fox2 < 0.4 Bs->Ds(*) + Ds(*) - decays are CP- even states with large BF’s, leading to large DGs/Gs: Angle between B thrusts: |cos q| < 0.8 DGs Bf(Bs->Ds(*) + Ds(*) - ) should be compared with direct measurement to test SM. ~ ~ <= Gs 1- Bf(Bs->Ds(*) + Ds(*) - ) / 2 Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Exclusive Bs -> g g decay AAAA Exclusive Bs -> g g decay Bs -> g g MC DE Natural mode to search for BSM effects, many theoretical papers devoted to this decay. In SM: Bf(Bs-> gg ) = (0.5 -1.0) x 10-6 BSM can increase Bf up to two orders MC Fox2 < 0.5 |cos q| < 0.8 90% CL UL with 1.86 fb-1 : Bf(Bs -> gg ) < 0.56 x 10- 4. Better than PDG limit : < 1.48 x 10- 4 Many “conventional” BSM models can be better constrained by B -> K* g and B->s g g processes, however not all. In some BSM models Bs ->gg provides the best limit, in particular in 4-generation model (VTs) and R- parity violation SUSY ( x M(gg)). Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy AAAA Signals with 50 fb-1 Bs -> Ds(*)+ Ds(*)- - CP eigenstate Bs -> g g - intrinsic penguin Bs -> K+ K- - penguin Bs -> f g - radiative penguin Bs -> DsJ p - tree with DsJ Bs -> Ds+ K- - Cabibbo suppressed Bs -> Ds+l - n - exclusive leptonic Bs -> D0 KS0 - color suppressed Bs lifetime Bs semileptonic It seems, very strong physics program can be performed with 50 fb-1: Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy AAAA Conclusions Inclusive production branching fractions of J/Y, D0 and Ds mesons are measured at Y(5S). Ratio of Bs meson production over all bb-events is measured: fs = (16.4 ± 1.4 ± 4.1 )% Significant exclusive Bs signals are observed in Y(5S) -> Bs* Bs* channel. Combining all studied decay modes, mass of Bs* meson was measured: M(Bs*) = 5418 ± 1 ± (acc. err) MeV/c2, and mass of Bs was measured: M (Bs) = 5370 ± 1 ± 3 MeV/c2. Obtained Bs mass is in agreement with recent CDF measurement M (Bs) = 5366.0 ± 0.8 MeV/c2. Good agreement with published CLEO results is obtained in both inclusive and exclusive analyses. Our Y(5S) dataset is 4.4 times larger than CLEO dataset, providing better accuracy. Rare Bs decays are searched for at Y(5S) for the first time. Many new interesting results can be obtained with 50 fb-1. Significant signals are expected in many Bs decays with 50 fb-1 (maybe 30 fb-1) Engineering runs demonstrated, that background level is not large for studied decay modes. Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy AAAA Background slides Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

CDF: Bs-> Ds-p+ decays Results with 119 pb-1 : fs Bf( Bs -> Ds- p+) = 0.35 ± 0.05 ± 0.04 ± 0.09 fd Bf( B0 -> D- p+) From PDG : fs / fd = 0.270±0.028 , fs is rate of “b quark” -> Bs Uncertainty of absolute branching fraction measurement dominates already by 10% uncertainty of fs/fd. Bf( Bs -> Ds- p+) = 1.4 ± 0.2(stat) ± 0.2(syst) ± 0.4(BF) ± 0.2(PR) Bf( B0 -> D- p+) Bs physics at Y(5S), SLAC seminar, Jan 17, 2006, A. Drutskoy