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Direct CP and Rare Decays. June 21, 2005 B Physics at Hadronic Machines, Assisi. Outline. Machine, Detector, Basic Method Direct CPV in K p Observation of p 0 p 0 Polarization in f K *, r + K * 0 Khh Dalitz Analysis Baryonic Modes. New Results only at LP05 and EPS.
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Direct CP and Rare Decays June 21, 2005B Physics at Hadronic Machines, Assisi
Outline • Machine, Detector, Basic Method • Direct CPV in Kp • Observation of p0p0 • Polarization in fK*, r+K*0 • Khh Dalitz Analysis • Baryonic Modes New Results only at LP05 and EPS
Electron 8 GeV Positron3.5 GeV KEKB B-Factory Tsukuba Mt. 3Km Υ(4S) (10.58GeV/c2) = 0.425
Luminosity 1 fb–1 per day peak luminosity = 15.81 /nb/sec (May 18, 2005)
e- e- e+ e+ B B B Signal Reconstruction In Υ(4S) rest frame: ∆E Mbc 1D-binned fit 2D-unbinned fit
Main background for hadronic rare B is continuum qq events. (q=u,d,s,c). Topology of continuum events and B decays are different. Choose |cosθThrust| S⊥ R2so R4so R2oo R3oo R4ooas input to Fisher, and combine it with cosθBto calculate the Likelihood Ratio. Define modified Fox-Wolfram moment: Use Fisher discriminant to optimize the coefficients. Υ(4S) B decay continuum events Background Suppression
Likelihood Ratio (LR) Optimize uds charm off reson. sideband
Evidence for DCPV in B Kp Y. Chao, P. Chang et al. PRL 2004 CLEO 1999 (PRL 2000) 253 fb–1 214053 evts ACP(K+p–) = –10. 1 ± 2.5 (stat) ± 0.5 (syst) % w/ BaBar > 5s 3.9s
AKp, AppSizable Ali @ ICHEP2004 Belle SU(3) relatesApp= -3AKp (Gronau & Rosner) BaBar Sizable T-P Strong Phase
AKp0≠AKp? Y. Chao, P. Chang et al. PRL 2004 253 fb–1 72834 evts ACP(K+p0) = 4 5 2% 2.4s from K+p- (3.6sw/ BaBar) Large EWPenguin? Large C ? d p0 _ d b s B- K- u u
Observation of B0p0p0 Y. Chao, P. Chang et al. PRL 2005 253 fb–1 8216 evts B = (2.32 ) x 10-6 0.44 0.48 0.22 0.18 5.8 s Use same flavor-tagging as TCPV analysis ACP = 4417% 53 52 Main limiting factor for f2 program from pp
Polarization in B fK* fK* polarization anomaly? But …?
Polarization in B fK* K.F. Chen et al., hep-ex/0503013, to appear PRL 253 fb–1
fK* Polarization transversity basis Naively
Angular Analysis for fK* Polarization Confirm fL ~ 0.5 4.3sevidence for FSI (strong phase)
New Physics Test with fK* Polarization T-odd CPV Datta & London 2004
Polarization in B r+K*0 J. Zhang et al., hep-ex/0503013, submitted PRL 253 fb–1 (2-d unbinned fit projections) Non-resonant r+K+p– Significant Take into account in Angular Analysis
Angular (fL) Analysis for r+K*0 helicity basis A0 A± NR-rKp Another pure-PfL ~ 0.5
KhhDalitz Analysis Summary A. Garmash et al., hep-ex/0412066, submitted PRD 140 fb–1
Model Kππ-AJ: SAJ(Kππ) = A1(K*(892)) + A0(K*0(1430)) + AJ(fX(1300)) + A0(cC0) + A1(ρ(770)) + A0(f0(980)) B+ K+π+π-: Model Fitting to Signal L=140 fb-1 Model Kππ-A0 Model Kππ-A0 fit the data with different spin assumptions
Model KKK-BJ: Helicity angle distributions: SBJ(KKK) = A1(φ(1020)) + AJ(fX(1500)) + A0(cC0) + ANR ANR Parameterizations used: ANR(s13,s23) = a1(e-βs13 + e–βs23)eiδ fX(1500) is best fit with the scalar hypothesis B+ K+K+K-: Model Fitting to Signal L=140 fb-1 Model KKK-B0 ANR(s13,s23) = a1eiδ ANR(s13,s23) = a1[(1/s13)b+ (1/s23)β]eiδ Model KKK-B0 fX(1500) φ(1020)
Null asymmetry tests: • qq related background: ACP(qq)=(-0.83±1.30)% • BB related background: ACP(BB)=(-1.15±2.18)% • B->Dπ->Kππ signal: ACP(Dπ)=(-1.16±0.86)% Search for DCPV in B± K±π+π- 253 fb–1 3115±92 evts N(B-) = 1637±68 N(B+) = 1492±65 preliminary N(K-π-π+) – N(K+π+π-) ACP(K±π+π-) = = (+4.6±3.0 ) % +1.7 -1.2 N(K-π-π+) + N(K+π+π-) Considered as a systematic error due to detector asymmetry
DCPV Hint in B+ ρ0K+ 253 fb–1 A 2.4σ hint for Direct CP violation in B±->ρ(770)0K± preliminary ACP(ρ0K±) = 27 ± 12 ± 2 % +59 - 3
Improved B+ ppK+ Measurement M.Z. Wang et al., PLB 2005 140 fb–1 21717 evts Threshold Peaking BF: 4.59 ± 0.50 x 10-6 (4.89 x 10-6, PRL92, 131801, 2004) Two-body not yet seen. +0.38- 0.34
B0 LL, Lp, pp and other 140 fb–1 M.C. Chang et al. PRD 2005 90% confidence level UL: B0pp< 4.1 x 10-7 B0Lp< 4.9 x 10-7 B0LL< 6.9 x 10-7 Belle:B+ J/pL < 4.1 x 10-5 BABAR:B+ J/pL< 2.6 x 10-5 B+ J/pp<1.9 x 10-5 BABAR, 81fb-1 Belle, 78fb-1
threshold peaking threshold peaking Threshold Peaking: ppKs &pLp
Angular Distribution: ppK+ p Өp X K+ bs dominant process Fragmentation picture p at pp rest frame s u K+ p u d u u s u u d p ppK signal Proton against K- (p against K+) : flavor dependence! (Expect symmetric distribution if effective 2-body)
Outline • Machine, Detector, Basic Method • Direct CPV in Kp • Observation of p0p0 • Polarization in fK*, r+K*0 • Khh Dalitz Analysis • Baryonic Modes New Results only at LP05 and EPS
Previous B+ ppK+,ppp+Measurement M.Z. Wang et al., PRL 2004 78 fb–1 Threshold Peaking