Presentation on theme: "CKM Fits: What the Data Say Stéphane T’Jampens LAPP (CNRS/IN2P3 & Université de Savoie) On behalf of the CKMfitter group"— Presentation transcript:
CKM Fits: What the Data Say Stéphane T’Jampens LAPP (CNRS/IN2P3 & Université de Savoie) On behalf of the CKMfitter group
The CKM Matrix: Four Unknowns Measurement of Wolfenstein parameters: from |V ud | (nuclear transitions) and |V us | (semileptonic K decays) combined precision: 0.5% from |V cb | (inclusive and exclusive semileptonic B decays) combined precision: 2% from (mainly) CKM angle measurements: combined precision: 20% ( ), 7% ( ) W –W – Q q V qQ Q q
Inputs: m s 17 < m s < 21 ps C.L. hep-ex/ hep-ex/ m s : (stat.) ± 0.07 (syst.) ps
Inputs (major changes): sin 2 “The” raison d’être of the B factories: ICHEP ‘06 Conflict with sin2 eff from s-penguin modes ? (New Physics (NP)?) ± ± [BABAR(348m)] ± ± [Belle (532m)] sin2 = ± (0.023 stat-only) NB: a disagreement would falsify the SM. The interference NP/SM amplitudes introduces hadronic uncertainties Cannot determine the NP parameters cleanly C(J/ ) = ± ± [BABAR] ± ± [Belle] ± (0.017 stat-only) 0.55 ± 0.11 ± 0.02 [BABAR(347m)] 0.64 ± 0.10 ± 0.02 [Belle (532m)] sin2 ( ’K 0 )= 0.60 ± ± 0.34 [BABAR(347m)] 0.44 ± 0.27 ± 0.05 [Belle (386m)] sin2 ( K 0 )= 0.31 ± 0.21 NP can contribute differently among the various s-penguin modes Meaning of the average?
Inputs (major changes): angle Tree : dominant Penguin : competitive ? Time-dependent CP analysis of B 0 + – alone determines eff : but, we need ! realistic scenario Time-dependent CP observable : ( can be resolved up to an 8-fold ambiguity within [0, ]) Isospin analysis
Isospin Analysis: B→ B A B AR (347m) Belle (532m) Average S –0.53 ± 0.14 ± 0.02–0.61 ± 0.10 ± 0.04–0.58 ± 0.09 C –0.16 ± 0.11 ± 0.03–0.55 ± 0.08 ± 0.05–0.39 ± 0.07 “agreement”: 2.6σ BABAR & Belle
Isospin Analysis: B→ B A B AR (347m) Belle (275m) Average S –0.19 ± ± 0.41 ± 0.09–0.13 ± 0.19 C –0.07 ± 0.15 ± ± 0.3 ± 0.09–0.06 ± 0.14 BABAR & Belle = [ 94 ± 21 ] º Isospin analysis : 0.86 ± 0.06 f L 00 B A B AR (347m) (1.2±0.4±0.3)x10 -6 BR
Isospin Analysis: angle B→ / / B→ : at very large statistics, systematics and model-dependence will become an issue B→ρ Dalitz analysis: model-dependence is an issue ! B-Factories = [ 93 ] º Global Fit = [ 98 ] º (include new Dalitz BABAR)
Putting it all together t h e g l o b a l C K M f i t Inputs:
The global CKM fit: Testing the CKM Paradigm CP-insensitive observables imply CP violation ! CP ConservingCP Violating Angles (no theory)No angles (with theory)
ICHEP 2006 The global CKM fit: Testing the CKM Paradigm (cont.) [No NP in I=3/2 b→d EW penguin amplitude Use with (charmonium) to cancel NP amplitude] Tree (NP-Free)Loop CKM mechanism: dominant source of CP violation The global fit is not the whole story: several F=1 rare decays are not yet measured Sensitive to NP
Radiative Penguin Decays: BR(B→ )/BR(B→K* ) Belle (386m) B A B AR (347m) 1.06 ± ± 0.07 ++ 00
Hypothesis: NP in loop processes only (negligible for tree processes) Mass difference: m s = ( m s ) SM r s 2 Width difference: s CP = ( s ) SM cos 2 (2 -2 s ) Semileptonic asymmetry: A s SL =-Re( 12 /M 12 ) SM sin(2 s )/r s 2 S = sin(2 -2 s ) Grossman, PL B380, 99 (1996) Dunietz, Fleischer, Nierste, PRD 63, (2001) NP wrt to SM: reduces s enhances m s B s mixing phase very small in SM: = (deg) Bs mixing: very sensitive probe to NP UT of B d system: non-degenerated (h d, d ) strongly correlated to the determination of ( , ) UT of B s system: highly degenerated (h s, s ) almost independent of ( , ) NP Parameterization in B s system
0.2 fb -1 ( m s )= 0.035, (sin(2 )=0.1 m s, s and A s SL First constraint for NP in the B s sector Still plenty of room for NP Large theoretical uncertainties: LQCD h s ~<= 3 (h d ~<=0.3, h K ~<= 0.6) NP in B s System
Prospective: LHCb 2fb -1 (2010 ?)? assumptions: ( m s )=0.01 ( ) = 10º ( ) = 5º note: “expected” improvement from Lattice QCD is taken into account. (sin2 )=0.02
Conclusion CKM mechanism: success in describing flavor dynamics of many constraints from vastly different scales. With the increase of statistics, lots of assumptions will be needed to be reconsidered [e.g., extraction of from B→3 ,4 , etc., P EW, …] B s : an independent chapter in Nature’s book on fundamental dynamics there is no reason why NP should have the same flavor structure as in the SM B s transitions can be harnessed as powerful probes for NP ( : “NP model killer”) Before claiming NP discovery, be sure that everything is “under control” (assumptions, theoretical uncertainties, etc.) There are still plenty of measurements yet to be done
Do Not Miss: hep-ph/ Bayesian Statistics at Work: the Troublesome Extraction of the CKM Angle (J. Charles, A. Höcker, H. Lacker F.R. Le Diberder and S. T’Jampens)
G. Isidori – Beauty ‘03
Roger Barlow: YETI06Everything you wanted to know about limits Bayes at work = x P(0 events| ) (Likelihood) Prior: uniform Posterior P( ) 3 P( ) d = Same as Frequentist limit - Happy coincidence Zero events seen P(n; )=e - n /n!
Roger Barlow: YETI06Everything you wanted to know about limits Bayes at work again = x P(0 events| ) Prior: uniform in ln Posterior P( ) 3 P( ) d >> Is that uniform prior really credible? Upper limit totally different!
Roger Barlow: YETI06Everything you wanted to know about limits Bayes: the bad news The prior affects the posterior. It is your choice. That makes the measurement subjective. This is BAD. (We’re physicists, dammit!) A Uniform Prior does not get you out of this.