SLAC DOE Review, Jun CP Violation in Penguin Decays Denis Dujmic, SLAC

SLAC DOE Review, Jun New Physics in Loop Decays? FCNC Amplitude in SM 3-6 QCD penguin 7-10 EW penguin Dominant terms double-CKM and QCD-loop suppressed Decay rates small in Standard Model: < Heavy non-SM particles can appear in loops - large contribution possible, ~O(1) - in general not CP-conserving Study CPV in penguins: - probe for new CP-violating phases W

SLAC DOE Review, Jun Indirect CPV (beta) Tree decay, BF~10 -3 Both have same CP asymmetry parameter 2 Im[ ] = sin2  Test this prediction! Penguin decay, BF~10 -5

SLAC DOE Review, Jun Standard Model or Beyond? New Physics  This could be the greatest discovery of the century. Depending, of course, on how far down it goes. All penguins 0.50 ± 0.06 (3  difference!)

SLAC DOE Review, Jun SM Uncertainties CKM term Example diagram CPV Parameter SM pollution! t c u

SLAC DOE Review, Jun SM Uncertainties - Theory estimates Beneke, PLB 620 (2005) 143 Cheng, Chua & Soni, PRD72:094003(2005) -HFAG BaBar+Belle average -ccK average Predictions based on factorization models  sin2  QCDF, pQCD, SCET calculations agree

SLAC DOE Review, Jun Status of KKK 0 CP Analysis

SLAC DOE Review, Jun Event Selection for B 0 → KKKS All K + K - K S KSKS (530±28) (114±12) Branching fraction (reco. events)  K 0 makes only 15% of the total K + K - K 0 branching fraction What goes into B 0 → K + K - K 0 Dalitz plot? 230 M BB pairs

SLAC DOE Review, Jun B 0 → KKK 0 : CP Content CP of final state not known! - CP(K + K - ) = even, CP(K + K - K S ) = (-1) L - need distribution of angular momenta L Angular-moments analysis: K+K+ KK B0B0 KSKS L L’=L HH Compute wave strengths using moments of Legendre polynomials: Describe decay in terms of S and P-waves decaying into K + K - S-wave P-wave S-P interf.

SLAC DOE Review, Jun B 0 → KKK 0 : Angular Moments [BABAR,PhysRevD71:091102(2005)] BABAR’s – analysis of angular moments: Average moments computed using sPlot technique [Pivk, Le Diberder, physics/ ] Outside of  K S region BABAR 230 MBB Belle 386 MBB (isospin) Belle’s method requires 1.7 times more data to have same error

SLAC DOE Review, Jun Sin2  from KKK0 Dalitz plot of K + K - K S consists of  K S (CP-odd) + S-wave (CP-even): -split sample into  KS (CP-odd) and m(K + K - )>1.1 (CP-event) - treat any interference as syst. error KKK S In each mass region: K0K0 Belle BaBar “K + K - K 0 ” BaBar Belle K0SK0S K0LK0L BABAR, ~230MBB History plots of CP asymmetry measurements:

SLAC DOE Review, Jun What More? Dalitz plot! Time-dependent Dalitz plot rate: Natural way to combine  K 0 and high-mass KKK 0 decays Best way to treat interference effects Describe Dalitz plot amplitude in terms of (non)resonant components:

SLAC DOE Review, Jun Understanding KKK 0 Dalitz plot D +,D s +  reflections X(1500)  non-res [BABAR,hep-ex/ ]  c0 ModeFraction (%)  (1020)K S 15.4  3.4  0.6 X(1500)K S 5.2  2.2  0.9 (<8.3) 38.9  7.3  0.9 Non-resonant70.7  3.8  1.7  c0 K S 3.1  1.6  0.8 (<5.5) f 0 (980)K S 5.7  3.2  1.0 (<9.7) -First B 0 ->KKK S Dalitz plot analysis (time integrated) - Next: simultaneous fitting of entire Dalitz plot  K 0 +KKK 0 and extraction of CPV parameters m(K + K - ) [GeV/c 2 ] m(K ± K S ) [GeV/c 2 ]

SLAC DOE Review, Jun Other Progress in Penguins Improvements of BABAR analyses (using 230 M BB pairs): 1)Add submodes of existing channels: -K S ->    - is only 34% of all K 0 decays -Add K L :  ’K L, KKK L -Add K S ->     : K S K S K S 2) Add channels with high background: -     K S,  K S - Total penguin average for BABAR:  (sin2  ) ~ Stat. power from additional modes alone:  (sin2  ) stat ~ 0.16

SLAC DOE Review, Jun Performance for beta BABAR ~230 MBB Belle ~386 MBB Total error on sin2  as of Winter06 BABAR outperforms Belle even with less data - better analysis techniques - bigger boost, better PID

SLAC DOE Review, Jun Summary and Plans All channels will be updated with 2006 dataset -BaBar error on sin2  (  ’K0) < 0.1 -BaBar+Belle combined penguin error ~0.04 SLAC contribution: - KKK S K S →     (Dujmic), K S →     (Thompson,Roodman) -  K S, f 0 K S ->     K S (Graham) -  K S,  ->3  (Suzuki) -     K S (Allen, Roodman): - K  : (Allen, Roodman), - Dalitz plot: K + K S K S, K + K + K - (Thompson,Dujmic,Roodman) - conveners of physics working group (Dujmic,Graham) beta Direct CPV