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Measurement of B(Y(5S)  B s (*) B s (*) ) Using Beauty & Charm Decays

Measurement of B(Y(5S)  B s (*) B s (*) ) Using Beauty & Charm Decays. Radia & Sheldon. Y(5S), knowledge & Expectations ?. 1. Knowledge from CLEO 1.5 : σ (Y(5S))/ σ (cont) ~ 1/10. L=116 pb -1  No direct measurement of B s production cross section. 2. Expectations:.

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Measurement of B(Y(5S)  B s (*) B s (*) ) Using Beauty & Charm Decays

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  1. Measurement of B(Y(5S)  Bs(*)Bs (*)) Using Beauty & Charm Decays Radia &Sheldon

  2. Y(5S), knowledge & Expectations ? • 1. Knowledge from CLEO 1.5 : • σ(Y(5S))/σ(cont) ~ 1/10. • L=116 pb-1No direct measurement of • Bs production cross section. 2. Expectations: • Decay channels: • BdBd , BdBd* , Bd*Bd* , BsBs , BsBs* , Bs*Bs* , BdBd ππ ,BdBd π ,BdBd*π, B0B+ π. • UQM: • The B cross section dominated by B*B* and Bs*Bs* production. • Bs*Bs* production ~ 1/3 of the total Y(5S) cross section. σ(BsBs)+ σ(BsBs*)+ σ(Bs*Bs*) ~ 0.1nb. • Other models: Predict a smaller Y(5S)  Bs*Bs* component! • Need to investigate the composition of the Y(5S) and see how much Bs is produced. • It is of considerable interest to establish firmly the properties of Bs(mass, selected decay modes, production rate at the Y(5S), and possibly even Bs mixing, for which the data we have may not be sufficient but could lay the groundwork for a future study of this topic…

  3. Data Sample from CLEO III We used all the data we collected near or at the Y(4S) resonance and all the data taken right at the Y(5S) peak. with the CLEOIII detector.

  4. Use The Inclusive Ds± Spectrum to MeasureBr(Y(5S) Bs(*)Bs(*)), Why? In the simple spectator model the Bs decays into the Ds nearly all the time. Since the Br(B DsX) has already been measured to be (10.5 ± 2.6 ± 2.5)%, Dominant Decay Diagrams for a B meson into Ds meson we expect a large difference between the Ds yields at the Y(5S) and the Y(4S) that can lead to an estimate of the size of the Bs(*)Bs(*) component at the Y(5S). Dominant Decay Diagrams for a Bs meson into Ds meson

  5. Ds Spectra & Production Rates at the Y(4S) & at the Y(5S) Extracted from the fitted Ds invariant Mass Spectra On-Y(4S) Off-Y(4S) • Y(5S) • Y(4S) On-Y(5S) DATA BR(Y(4S)  Ds X) . Br(Ds  fp) = (8.0  0.2  0.9).10--3 BR (Y(4S)  Ds X) = (18.1  0.5  2.8)% BR (B  Ds X ) =(9.0  0.3  1.4)% Confirmed by BABAR:( 8.94 ± 0.16 ± 1.12 )% PDG (10.5  2.6  2.5)% Br(Y(5S)  Ds X) . Br(Ds  fp) = (19.8  1.9  3.8).10--3 BR (Y(5S)  Ds X) = (44.7 4.2 9.9)%

  6. Establishment & First Measurement of Bs production at the Y(5S) (NDs from Y(5S) -NDs from Y(4S))/NY(5S) Significant Excess of Ds yields at the Y(5S) BR (Y(5S) Ds X) / BR (Y(4S) Ds X) = 2.4  0.3 +0.6 -0.3 x (|p|/beamE) • Using: ourestimate of: BR (BsDsX) = 92 ± 11 % and Br(Ds-> fp) =(4.4 ± 0.5)% • We Measure: the ratio of Bs(*)Bs(*)to the total bb quark pair production at the Y(5S) energy:BR (Y(5S)  Bs(*)Bs(*)) = ( 16.0 ± 2.6 ± 5.8 ) %

  7. The Y(5S), a BS Factory. • 10+5/fb Bs mesons are produced at the Y(5S) • These results went in public in Spring 2004 • Belle Collaboration had an engineering run and collected 1.8fb-1 in summer 2005, adopted the same technique to confirm our results and tried to measure the different Bs decay Br’s  BUT the number of produced Bs mesons is definitely needed  Knowledge of the Bs production rate is crucial for the measurement of any Bs decay at the Y(5S). • However, the determination of fs in a model independent manner requires several tens of fb-1 (S. Stone & R. Sia, ``Model Independent Methods for Determining B(Y(5S)  BS(*)BS(*)),"[arXiv:hep-ph/0604201]) • The needed data sample has not been collected by any High Energy Physics detector thus far.

  8. Ds Analysis Updated BR(Y(4S)  Ds X) . Br(Ds  fp) = (8.0  0.2 +1.0–0.7).10--3 BR (Y(4S)  Ds X) = (22.9  0.6 +4.3-2.8)% BR (B  Ds X ) = (11.5  0.3 +2.1-1.4)% BR(Y(5S)  Ds X) . BR(Ds  fp) = (20.3  1.9 +3.8-2.4).10--3 BR (Y(5S)  Ds X) = (58.0 5.5 +13.5-8.5)% BR (Y(5S) Ds X) / BR (Y(4S) Ds X) = 2.5  0.2 +0.4-0.3 => BR (Y(5S)  Bs(*)Bs(*)) = ( 21.8 ± 3.4 +8.6-4.4 ) %

  9. Not only Ds , but other particle species also can be used at the Y(5S): Any particle specie that is produced more frequently from Bs mesons than from B mesons can be used, i.e: particles with an “s anti-s” quark content, Ds, eta, eta’, phi, … are good candidates.

  10. D0, D+ &Ds  η,η' and f Using 281 pb-1 & 71 pb-1 of CLEO-c data taken @ the 3770 & ~4170MeV respectively, we measured: ModeOur Measurement (%)PDG (%) • BR (D0 ηX) = 9.4 ± 0.4± 0.6 < 13 • BR (D0 ηX)= 2.6 ± 0.2 ± 0.2 -- • BR (D0 fX)= 1.0 ± 0.1± 0.1 1.7 ± 0.8 • BR (D+ ηX) = 5.7 ± 0.5 ± 0.5 < 13 • BR (D+ ηX)= 1.0 ± 0.2 ± 0.1 -- • BR (D+ fX)= 1.1 ± 0.1 ± 0.2 < 1.8 • BR (Ds ηX) = 32.0 ± 5.6 ± 4.7 -- • BR (Ds ηX)= 11.9 ± 3.3 ± 1.2 -- • BR (Ds fX)= 15.1 ± 2.1 ± 1.5 18 ± 15 10 * h, h & f are relatively rare in D decays while they are produced with much higher rates from Ds mesons. * Because Bs Decays primarily into Ds final states and due to this high rate of Ds  f, Bs decaying into f mesons can be a primary decay chain for Bs studies.

  11. Reconstruct from the remaining tracks and showers the observable particles in The Signal D Reconstruct one of the two D(s)’s in a hadronic decay channel, The Tagged D. The Analysis TechniquesUsed • D0,D- TagSelection L = 281 pb-1 • We require |DE| to contain 98.8% of the signal events (to be within 2.5 r.m.s widths of the peak value of each tag). e+e- • DSTagSelection • Loose cut on Ds Mbc, L = 71 pb-1 • At the 4170, the g*decays to: DD, D*D, D*D*, DsDs, DsDs* (Mostly to: D*D*, and DsDs* ) • Directly produced Ds  Narrow MBC , theindirect Ds Wide MBC (gsmearing) • Our main results are obtained using the Ds -> Kpp tagging mode only and the whole set of Ds tags is then used for the systematic study.

  12. f Invariant mass distributions Y(4S) on-Res data Y(4S) off-Res data 5014.3 ± 100.5 13,440.6 ± 167.9 Reconstruction Efficiency Y(5S) data 2704.5 ± 104.7 x (|p|/beamE) • Reconstruct f mesons in several x intervals

  13. Raw & Continuum Subtracted f yields vs x Extracted from the Data • Raw f spectrum • from the Y(4S) • on-Res data • ScaledRaw f • spectrum from • the Y(4S) off- • Res data Continuum subtracted f yields per resonance Number Of Events Y(5S)Y(4S) • Raw f spectrum • from the Y(5S) • on-Res data • ScaledRaw f • spectrum from • the Y(4S) off- • Res data Number Of Events x ( |p|/Ebeam ) x ( |p|/Ebeam )

  14. Partial & Total Branching Fractions Y(5S) Y(4S) BR(Y(4S)  fX) = (7.1  0.1  0.60.8)%, BR(B  f X ) = (3.53  0.05  0.320.39)% , ( PDG = (3.5 ± 0.7)%) Partial Branching Fraction x ( |p|/Ebeam ) BR(Y(5S)  fX) = (13.3  0.7  0.170.22)% BR(Y(5S)  fX) / BR(Y(4S)  fX) = 1.9  0.1  0.20.3

  15. BR(Y(5S)  Bs(*)Bs(*)) Using f yields We know that B(B -> f X) = B(B  D0X+D+X)*B(D0,D+f X) + B(B  DsX)*B(Dsf X) + B(frag+..) B(BS -> f X) = B(BS D0X+D+X)*B(D0,D+f X) + B(BS DsX)*B(Dsf X) + B(frag+..) Using our measurements of: [B(D0 f X) = (1.0 ± 0.1± 0.1)%] & [BR (D+ fX) = ( 1.1 ± 0.1 ± 0.2)% ] B(B  Ds X) = (11.5  0.3 +2.1-1.4)% B(Ds fX)= (15.1 ± 2.1 ± 1.5)% And our estimate of: B(BSDSX) = 92 ± 11 % B(BSDX) = 8 ± 7 % B(B -> f X) = [(0.235+0.640) x 0.151] + [0.115 x 0.151] +B(frag+..) = 3.53 % => B(frag  f X) = 0.9% B(BS -> f X) = B(BS D0X+D+X)*B(D0,D+f X) + B(BS DsX)*B(Dsf X) + B(frag+.) = [0.08 x 0.151] + [0.92 x 0.151] +B(frag+..) = (15 ± 3)% => BR (Y(5S)  Bs(*)Bs(*)) = ( 26.9 ± 3.1 +14.5-6.6 ) %

  16. Backups

  17. Mbc (Invariant Mass) of D(s) Tags from DATA D- Ds D0 K-p+p0 (227556 ± 617) D0 tags (151819 ± 487 D+) tags (5067 ± 112) Dstags • For D0(-) : The signal region is defined as containing: 98.8% of the signal events with mbc below the mbc peak, and 95.5% of the signal events above the peak. • For Ds : The signal region is defined ascontaining 98.8% • (2.5 r.m.s widths) of the signal events with invariant mass below and above the Dspeak.

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