CP Violation and CKM Angles Status and Prospects Klaus Honscheid Ohio State University C2CR 2007

K. Honscheid, Ohio State University, C2CR 2007 PEP-II at SLAC KEKB at KEK Belle BaBar 9 GeV (e  )  3.1 GeV (e + ) peak luminosity: 1.2  cm  2 s  1 Two asymmetric-energy B factories 8 GeV (e  )  3.5 GeV (e + ) peak luminosity: 1.7  cm  2 s  1 11 nations, 77 institutes, ~600 persons 13 countries, 57 institutes, ~400 collaborators The Two Asymmetric Energy B Factories

K. Honscheid, Ohio State University, C2CR 2007 Experimental Landscape (early 2007) Total Integrated Luminosity (fb -1 ) CLEO II CLEO II.5 BaBar Belle 710 fb fb -1 Tevatron > 2.4 fb -1 # of B decays recorded 1.3 Billion 0.8 Billion

K. Honscheid, Ohio State University, C2CR 2007 CP( ) = CP Violation in the Standard Model CP Operator: q q’ J g q JJ g* Mirror coupling To incorporate CP violation g ≠ g* (coupling has to be complex)

K. Honscheid, Ohio State University, C2CR 2007 CP Violation in the SM: The CKM Matrix The CKM matrix V ij is unitary with 4 independent fundamental parameters Unitarity constraint from 1st and 3rd columns:  i V * i3 V i1 =0 CKM phases ( in Wolfenstein convention ) u d t c bs V ud V us V ub V cd V cs V cb V td V ts V tb   arg[V ub *]  arg[V td *]

K. Honscheid, Ohio State University, C2CR 2007 Interfering Amplitudes in B o  K  Decays B 0  -  + B 0  +  - A 1 = a 1 e i  1 e i  1 A 1 = a 1 e -i  1 e i  1 Asymmetry = = ~ 2 sin(     ) sin(    2 ) = 0 A 2 = a 2 e i  2 e i  2 A 2 = a 2 e -i  2 e i  |A| 2 – |A| 2 |A| 2 + |A| 2  (B) –  (B)  (B) +  (B) Tree decay  Penguin decay Interference  (A 1 +A 2 ) 2 ≠ (A 1 +A 2 ) 2

K. Honscheid, Ohio State University, C2CR x 10 6 B 0 Mesons Count B 0  K +   Decays 227 x 10 6 B 0 Mesons Count B 0  K -  + Decays Is N( B 0  K +   ) equal to N( B 0  K -  + )? CP Violation in B o  K  Decays BABAR background subtracted

K. Honscheid, Ohio State University, C2CR 2007 Golden mode B 0  J/  K s :CP eigenstate, high rate, theoretically clean Mixing Induced CP violation B0B0 J/  K s e i0 e  i0 No weak phase B0B0 e  i2  Two Amplitudes InterferenceA CP ~ sin2  Two V td vertices e  i2  +

K. Honscheid, Ohio State University, C2CR 2007  (4S) t =0 A Complication: Quantum Coherence We need to know the flavor of the B at a reference t=0Flavor Tagging and measure the difference in decay time  tTime Dependence B 0 The two mesons oscillate coherently : at any given time, if one is a B 0 the other is necessarily a B 0 In this example, the tag- side meson decays first. It decays semi-leptonically and the charge of the lepton gives the flavour of the tag-side meson : l  = B 0 l  = B 0. Kaon tags also used. tag B 0 l  (e-,  -)  =0.56  z =  t  c rec  t picoseconds later, the B 0 (or perhaps its now a B 0 ) decays. B 0 At t=0 we know this meson is B 0 Time dependent asymmetry A CP = S CP sin(  m  t)  C CP cos(  m  t) S CP =  f CP sin2  (f CP = ±1), C CP “direct” CP violation = 0 for J/  K

K. Honscheid, Ohio State University, C2CR 2007 CP Violation in B 0  J/  K s  t for B 0 tag  B 0  J/  K Background BaBar preliminary, hep-ex/ Belle preliminary, hep-ex/ B 0  J/  K S B 0  J/  K L Belle Preliminary Belle Preliminary B 0 tags  t asymmetry J/  K L is f CP = +1 J/  K S is f CP =  1  t oscillation Period = B mixing  m Amplitude = D sin2  (Dilution D due to mistags; measured experimentally) PRL 98, (2007)

K. Honscheid, Ohio State University, C2CR 2007 Extracting  from sin2  has ambiguities; removed by J/  K*, D* D *K S and D  0 /  /  '/  analyses Sin(2  ) World Average Heavy Flavors Averaging Group E.Barberio et al., hep-ex/ Statistics limited Consistent with zero: no evidence for NP in tree decay  = 21.2 o ± 1.0 o

K. Honscheid, Ohio State University, C2CR 2007 Is “  ” Universal? Can use 3 different categories of B 0 decays to measure  : golden mode Possible contribution from New Physics (NP): new heavy particles in the loop See the following talk by Tom Browder News Flash hep/ex B  D + D - S = ± 0.37 ± 0.09 A = 0.91 ± 0.23 ± 0.06 (= -C) (expected to be close to 0)

K. Honscheid, Ohio State University, C2CR 2007 Let’s try this for the next angle:  Access to  from the interference of a b → u decay (  ) with B 0 B 0 mixing (  ) B 0 B 0 mixing Tree decayPenguin decay  Inc. penguin contribution How can we obtain α from α eff ? Time-dep. asymmetry :  NB : T = "tree" amplitude P = "penguin" amplitude

K. Honscheid, Ohio State University, C2CR 2007 How to estimate |  eff | : Isospin analysis Use SU(2) to relate decay rates of different hh final states (h  {  }) Need to measure several related B.F.s Gronau, London : PRL65, 3381 (1990) 2|  eff | Limiting factor in analysis

K. Honscheid, Ohio State University, C2CR 2007 Measuring  in B   hep-ex/  ±0 ±0  0 0 0 0   C.L. hep-ex/ ±65 S  +  - = ± 0.1 ± 0.04 A  +  - (=-C) = 0.55 ± 0.08 ± 0.05 BR  +  - = (5.1±0.2±0.2) x +-+-

K. Honscheid, Ohio State University, C2CR 2007 Sometimes you have to be lucky 615±57 390±49 B   is almost completely polarized B      is small better constraint on  hep-ex/ hep-ex/ hep-ex/ B  B   B  B   B  B  

K. Honscheid, Ohio State University, C2CR 2007 Combining all methods:  Combined:  = [  9 ]  CL=0.683 Other solutions disfavoured  Global Fit = [ ] º Global fit without  :

K. Honscheid, Ohio State University, C2CR 2007  = arg[V ub *]: CP violation in DK modes Relative phase = e  i  B+B+ D0K+D0K+ eiei eiei V* ub vertex e i  E.g. B +  D 0 / D 0 K + D0K+D0K+ D 0 / D 0  CP state (GLW) D 0 / D 0  K   + /K +  , CA/DCS (ADS) D 0 / D 0  K S  +  , Dalitz (GGSZ) D decays do not involve V ub or V td : no contribution to phase GLW: Gronau, London, Wyler (2001) ADS: Atwood, Dunietz, Soni (1997) GGSZ: Giri, Grossman, Soffer, Zupan (2003) eiei eiei B ±  DK: no time dependence; extract  from rates and CP asymmetries but b  u amplitude is small (for example r B (DK − ) = 0.16 ± 0.05 ± 0.01 ± 0.05 Belle)

K. Honscheid, Ohio State University, C2CR 2007 The GGSZ method – an example BaBar preliminary; hep-ex/ Belle; Phys.Rev.D 73, (2006) Belle Map out Dalitz plot from all D 0  K s  +  - decays B+B+ BB Look for deviations in B ±  D 0 K ± plots

K. Honscheid, Ohio State University, C2CR 2007 Combined Result for  Indirect (CKM)  = [59 +9  4 ]  Combined:  = [  24 ] 

K. Honscheid, Ohio State University, C2CR 2007 The CKM Model has passed the experimental test New Targets Effects of TeV new physics  deviations from SM LFV and new source of CPV Hidden flavor symmetry and its breaking [21.2 ± 1.0] o (0,0)   [ ] o [ ] o 

K. Honscheid, Ohio State University, C2CR 2007 The next few years (2007 – 2010) Belle and BaBar 1 ab -1 (2006) 2 ab -1 (2008) Tevatron 2 fb -1 (2006) 8 fb -1 (2009) LHCb is nearing completion ICHEP08

K. Honscheid, Ohio State University, C2CR 2007 LHCb Prospects (Some of the things they can do) B s Mixing phase (  s ) using B s  J/  Signal yield: 130k events per L=2fb -1 with a B/S  0.1, Sensitivity  s ~ Sensitive probe of New Physics effects in the B s mixing  s =  s (SM) +  s (NP) with  s (SM)=-2 2  ~ ±0.002 now pre-LHCb LHCb at L=2fb -1 LHCb at L=10fb -1 year (s)(s) now pre-LHCb LHCb at L=2fb -1 LHCb at L=10fb -1 (s)(s) Sensitivity to  Standard methods Golden Mode B s  D s K Sensitivity ~ 4.2 o with 2 fb -1  (  ) [ o ] now pre-LHCb with LHCb at L=2fb -1 with LHCb at L=10fb -1 year V. Vagnoni CKM2006

K. Honscheid, Ohio State University, C2CR 2007 Summer 2006 From B-Factories to LHCb – without new physics 2008* LHCb L=10 fb

K. Honscheid, Ohio State University, C2CR 2007 Super B-Factory Plans at KEK and Frascati Interaction Region Crab crossing  =30mrad.  y*=3mm New QCS Linac upgrade More RF power Damping ring New Beam pipe L = 8  /cm 2 /sec Design Luminosity ~ 1 x /cm 2 /sec Synergy with ILC Recycle components (PEP, BaBar) Lots of R&D needed KEK Frascati IPIP ILC ring ILC FF

K. Honscheid, Ohio State University, C2CR 2007 Summary CKM Model is now a tested theory Great success for theorist Great success for experimentalist Great success for the Standard Model  = ( ) o  = (21.2 ± 1.0) o  = ( ) o Search for Deviations from SM and New Physics Near Term Future Looks Promising B Factories only half way done Tevatron will triple data sample LHC(b) turn on Long Term Prospects LHC(b) upgrades Super B Factories (KEK, INFN)