Summary of WG5 Gianluca Cavoto INFN Roma La Sapienza On behalf of WG5 conveners Robert Fleischer Karim Trabelsi Jure Zupan CKM Workshop 2006 in Nagoya 1
Overview The charge The main goal is the measurements of the angles φ 3 (γ) and φ 1 (β) from B decays involving D or Charmonium mesons. The limitations and ways to overcome them will be discussed, as well as new approaches and high statics projections. Measurement of φ 1 (β) in B decays to Charmonium. Measurements of φ 1 (β) and cos2φ 1 (cos2β).» CPT/T parameters. Measurements of φ 3 (γ) in B D (*) K (*) decays.» GLW and ADS methods.» Dalitz methods (model dependent/independent). Measurements of 2φ 1 + φ 3 (2β + γ) in B D (*) π,rdecays and related BF measurements (D s π,, Dπ 0, and D (*) K (*) ). Determine CP quantities with New Physics contributions expected very small NB: Phase of B s mixing in Joint sessions with WG3/6 2
B from b " ccs still golden! Still a golden channel to measure B d mixing phase Single diagram (tree) dominated, clear SM prediction S. Mishima: Some discussion on reliability of the evaluation 3
Time dependent CP violation At B-factory e - : 8.0 GeV e - e + e + : 3.5 GeV ϒ(4S) βγ ~ 0.425 Flavor tag B tag Δz B CP f CP(b ccs) Δz cβγδt B ~ 200 µ m $ z c(!" ) # $ t Effective tagging efficiency: (29.2+-1.4)% C = - A Combined with angular/dalitz analyses 4
Experiment input and theory wisdom A.Gaz M.Ciuchini BaBar 5
Belle results on 535 M BB B " J/! K CP 0 S B " J/! K CP 0 L Entries / 0.5ps Entries / 0.5ps Raw Asymmetry (= ξ CP sin2φ 1 sinδmδt) ξ CP = -1 ξ CP = +1 Raw Asymmetry Δt (ps) Δt (ps) sin2" = + 0.643 ± 0.038 sin2! = + 0.641 ± 0.057 A 1 B " J/! K CP 0 S (total) =! 0.001± 0.028 A 1 B " J/! K CP 0 L = + ± (total) 6 0.045 0.033
BaBar results K.George Still an average on many modes, to be splitted for publication 7
Experimental systematics Asymptotically dominated by vertexing Yu Nakahama Total error Statistical error Systematic error 535MBB 0.492/ab 5/ab 50/ab No limitation at 2 ab -1 L /ab ΔS from B 0 J/ψ π 0 : 0.000 ±0.007 (Ciuchini) 8
Solve ambiguity: cos2β Method based on interference between amplitudes Coefficient of sin term Different channels proposed and studied B J/ψK* (angular analysis) B 0 D 0 h 0 (D Dalitz analysis) B 0 D*D*K S (angular separation) Need an input on hadronic decay model 9
DDK A.Datta 10
BaBar results K.George Integral over Dalitz plane 11
b " cud transition: B D 0 h 0 A.Gaz D 0 flav tagged decay Positive solution is favored at Belle (386 M): 98.3% C.L. BaBar (311 M): 87% C.L. 12
Summary on φ 1 /β Reference measurement for any NP search Investigate more channels but keep them separates (along with friends) b d transition NP phase already well constrained by current data 13
R. Covarelli CPT CP/T violation 14
Outlook for A SL» Charge asymmetry in background and particle identification 15
Where penguins can sneak in Angular analysis for VV Still useful (see after) 16
S.Fratina Large CP asymmetry! Belle B 0 D + D - 17
sin(2β+γ) from tiny asymmetry Too small asymmetry: need external input on r Cheng-Wei Chiang: time-integrated measurements BaBar and Belle: time-dependent analyses 18
S.Ganzhur Current results K.Abe Full reco [D(*)π] BaBar 232 M Belle 386 M World average Partial reco [D*π] Still dominated by statistical error!!! 19
Can we estimate r reliably? M. Baak 0 B b Vcs d u s c D + (* ) S! " SU(3) 2 Vcs 20 V! cd 0 B b Vcd d u d ( ) c * D +! " Three potential sources of SU(3) breaking between D (*) h and D (*) s h : 1. Unknown SU(3) breaking uncertainty from non-factorizable contributions 2. Final state interactions: different rescattering diagrams 3. Missing W-exchange diagrams in calculation [1] I. Dunietz, Phys. Lett. B 427, 179 (1998) Prediction for r in different channels with errors 2β+γ back in UT fits? 20
Good idea (for the future) 2β+γ from time-dependent Dalitz analysis of B 0 D - K 0 π + F. Polci 10% error on 10 ab -1 21
Measurements of γ in B D 0 K Basic idea Tree level only B " A B D 0 K " A D f A B r B e i(δ Β -γ) D 0 K " AD Multiple incarnations: D decay to CP eigen., flavour eigen., multibody decays Use of D* 0 (both D 0 π 0 and D 0 γ!) and K* Neutral and charged B decays 22
B - D 0 (K S π + π - )K - Pictorially: 2 2 A( m K +, m! " Ks" s ) 2 (assuming СР-conservation in D 0 decays) Amplitude ratio: r B * V 0 ubvcs!!! 0! = A( B " D K ) / A( B " D K ) "![color supp] ~ 0. 1 * V V cb us Higher r B higher sensitivity Extract from data Need input for D decay amplitude High D 0 flavour tagged sample: Dalitz model 23
A. Poluetkov Belle data set Belle result (357 fb -1 ) [hep-ex/0604054, PRD 73, 112009 (2006)] B ± DK ± B ± D*K ± B ± DK* ± 331±17 events 81±8 events 54±8 events B - B + B - B + B - B + 24
Belle fit results Fit parameters are x ± = r B cos(±φ 3 +δ) and y ± = r B sin(±φ 3 +δ) (better behaved statistically than,",! ) Unbinned maximum likelihood fit with event-by-event background treatment (ΔE-M bc included into likelihood) r B 3 B ± D*K ± B ± DK* ± B ± DK ± +0.072 x = 0.025-0.080 +0.093 y = 0.170-0.117 +0.069 x + = 0.135-0.070 +0.090 y + = 0.085-0.086 +0.167 x - = 0.128-0.146 +0.172 y - = 0.339-0.158 +0.120 x + = 0.032-0.116 +0.137 y + = 0.008-0.136 +0.249 x = 0.784-0.295 +0.440 y = 0.281-0.335 +0.177 x + = 0.105-0.167 +0.164 y + = 0.004-0.156 25
F.Martinez Vidal BaBar results 316 fb -1 D 0 K D *0 K B + D 0 K * B + B d d = 2 r sin! " 0 # direct CPV B r B- r B+ 2γ B Dalitz model systematic error 26
Extracting γ Statistical treatment (in the end r B determines the error) BaBar Belle! mod 180 = (92 ± 41± 11± 12) Dalitz model error No 2 " constraint on! r B ( r ) < 0.142 < 0.198 B ( rb ) 0.016 < r * < 0.206 * < 0.282 B Combined for 3 modes: φ 3 =53 +15 ±3 (syst)±9 (model) -18 8 <φ 3 <111 (2σ interval) r DK =0.159 +0.054 ±0.012(syst)±0.049(model) -0.050 CPV significance: 78% r D*K =0.175 +0.108 ±0.013(syst)±0.049(model) -0.099 r DK* =0.564 +0.216 ±0.041(syst)±0.084(model) -0.155 27
S. Descotes-Genon Dalitz plot, resonaces, K-matrix Isobar Approximation K-matrix parametrization for overlapping resonances Better for ππ S-wave description 28
F.Martinez Vidal Dalitz Model (BaBar) Fit to scattering data Total fit fraction: 111% Anisovich & Sarantev, Eur. Phys. Jour. A16, 229 (2003) m 2 π+π (GeV2 /c 4 ) χ 2 /dof 1.2 unchanged, since dominated by Kπ P-wave 29 ππ S-wave ππ P,Dwaves DCS CA K*π K*π
Theory helps J.Zupan Model independent Unknowns: CLEO-c CP tagged Sample! 30
A. Poluetkov Binned analysis of CLEO-c data -i i Number of events in D 0 -plot: Number of events in B-plot 2 M h [ K + r K + K K ( xc + i = B i B! i i! i Number of events in D CP -plot Ki i ys i )] N = i hcp! [ K + i K ±! i 2 KiK ici ] Ci =< cos!" ( D ) > D S i =< sin!" ( D ) > D C 2 i 2 + S i! 1 ( =1 if bin size is small enough) C i, S i can be obtained from B data (M i ) only Very poor sensitivity C i from D CP, S i from B data Poor sensitivity for y S i constrained as i 2 1 Ci S = ±! Bias if bin size is large 31
D.Asner Impact of CLEO-c r B = 0.2 32
Summary on γ D 0 K (D 0 multibody) less promising r B small, probably 0.1 Progress on Dalitz model Eventually use CLEOc data to reduce model dependance ADS and GLW useful in conjunction with Dalitz No signal for ADS yet (P.Krokovny) Neutral D 0 K *0 : r B bigger? Feasibility study: BaBar 350 fb-1 σ(γ) 50 if r b = 0.35 ± 0.15 (V.Sordini) Drop-in-the-bucket strategy for next years Collaboration started among exp s for common Dalitz model systematic 33
Looking at V ub and γ and sin2β P.Ball Combine several γ determination (some of them questionable) 34
R. Fleischer More ideas for the future 35
Very clean B d mixing phase 36
CDF results A. Rahaman 360 pb -1 1fb -1 to be analized 37
LHCb projected performance M.Patel B mode D mode σ(γ) B + DK + Kπ + KK/ππ + K3π 5º - 15º B + D*K + Kπ B 0 DK *0 K s ππ Under study B + DK + K s ππ 8º B + DK + KKππ 15º B + DK + Kπππ Under study B 0 DK *0 Kπ + KK + ππ 7º - 10º Under study B s D s K KKπ 13º Signal only Combining all modes, with a nominal year of data (~2 fb -1 ), LHCb will be able to extract γ from combined analysis B DK with the ~5º precision required to match the indirect determination 38
G.Martinelli (WG6) Outlook Next two years (B-factory 2ab -1, CDF >1fb -1 )» β measurement still statistically dominated (Theory under control)» γ sensitivity, depends on real value of rb Can profit of multiple modes» Some information on Bs mixing phase? LHCb» Will play a role in γ with analysis of several modes Super Flavor factory» Run at charm threshold to lower model error» High statistics, ultimate precision (β, γ, A SL ) 39