August 20, 2007 Charmless Hadronic B decays at BaBar1 Charmless Hadronic B Decays at BaBar Woochun Park University of South Carolina Representing the BaBar Collaboration Physics University August 20, 2007

Charmless Hadronic B decays at BaBar2 Standard Model Supersymmetry Introduction to Charmless Decays Dominated by SM-suppressed b  u tree amplitudes. Also, transitions involving b  s and b  d penguin amplitudes. Small branching fractions, ~10 -6 in Standard Model Virtual loops sensitive to new physics contributions. Important probes of the CKM mechanism ( , , and  ) Rich program at the B factories Branching fractions and CP asymmetry measurements Polarization measurements in vector-vector and vector-tensor modes.

August 20, 2007Charmless Hadronic B decays at BaBar3 Overview of This Talk Vector-Vector and Vector-Tensor modes B +   K * (892) + [ arXiv: [hep-ex] ] B 0   K * (892) 0 and  K * 2 (1430) 0 [PRL (2007)] Search for B 0   (K  )* with large K  invariant mass [arXiv: [hep-ex]] B  K *  [PRL (2006)] BR’s, CP asymmetries, and polarization measurements

August 20, 2007Charmless Hadronic B decays at BaBar4 BaBar Dataset and Detector Need large data samples to probe BF~10 -6 > 420 fb -1 delivered. 223M or 384M B pair samples used for analyses presented here. BaBar Detector for Charmless B decay analyses Good neutral energy resolution Charged K/  separation more than  with Cherenkov angle + dE/dx. Cherenkov angle

August 20, 2007Charmless Hadronic B decays at BaBar5 Analysis Method Perform maximum likelihood fit Kinematic variables: beam energy substitute mass (m ES ),  E, resonance invariant masses and helicity angles. Event-shape variables to distinguish from continuum event Simultaneous fit to extract Branching fraction, CP asymmetries, and polarization parameters.  Kinematics  |cos  s |

August 20, 2007Charmless Hadronic B decays at BaBar6 B  VV, VT Decays : Helicity Amplitude and Angular analysis Full amplitude ananlysis can be simplified to separate longitudinal and transverse events with low statistics and measure: Longitudinal polarization fraction f L Integrate over  B   K* analysis B   K* analysis

August 20, 2007Charmless Hadronic B decays at BaBar7 Amplitude Standard Model: left-handed quarks and spin flip suppression:

August 20, 2007Charmless Hadronic B decays at BaBar8 Expectation of f L We expect longitudinally polarized decays to dominate: Confirmed (f L ~ ) in B  ,  (tree-dominated). Need to investigate pure penguin or penguin-dominated VV and VT decays. Other amplitudes could decrease f L : SM: annihilation contribution, re-scattering effect, magnetic penguin, small B  K* form factor…… NP: Right-handed supersymmetric mass insertions, tensor Z”,… fLfL   0.82±0.11  0.91±0.05  0.86±0.13  0.97±0.02 Tree-dominated VV results

August 20, 2007Charmless Hadronic B decays at BaBar9 Major Background Continuum Background |cos   | < 0.8 and Fisher PDF with cos  B and L 0, L 2. Charmed B Background D s /D    cut on 12 MeV of the nominal mass values. K  S-wave LASS shape is used with interference considered in the nominal fit. f 0  KK Interference effect is estimated as systematics.

August 20, 2007Charmless Hadronic B decays at BaBar10 Finding B +   K* + (892) Q is charge of pion.

August 20, 2007Charmless Hadronic B decays at BaBar11 Finding B 0   K* 0 (892) and B 0   K* 2 0 (1430)

August 20, 2007Charmless Hadronic B decays at BaBar12 Angular Distribution in Slices |A 0 | 2 expected to be dominant 

August 20, 2007Charmless Hadronic B decays at BaBar13 Measurement of f L  K * (892) 0  K * 2 (1430) 0  K * (892) + VV VV and VT different

August 20, 2007Charmless Hadronic B decays at BaBar14 Resolved Ambiguity in B +   K*(892) + with Interference without Interference

August 20, 2007Charmless Hadronic B decays at BaBar15 Resolved Ambiguity in B 0   K*(892) 0

August 20, 2007Charmless Hadronic B decays at BaBar16 Puzzles  K * (892) +     the difference b/w the Q  projections for events with cos   cos    and with cos   cos    0 or  Indicating the presence of final state interactions for VV. (not accounted for by naïve factorization). f L (VV) ≠ f L (VT) (puzzle) Indication of a new physics contribution  FSI Effect

August 20, 2007Charmless Hadronic B decays at BaBar17 Theoretical Efforts FPCP 2007 presented hep-ph/ , PLB 601,151 (2004). hep-ph/ , PLB 597,291 (2004), PRD 71, (2005), PRD 70, (2004).

August 20, 2007Charmless Hadronic B decays at BaBar18

August 20, 2007Charmless Hadronic B decays at BaBar19

August 20, 2007Charmless Hadronic B decays at BaBar20 Search for  (K  )* 0 with large K  invariant mass We extend the B   K * (892) 0 analysis to higher-mass and higher-spin resonances. However, B   D 0 is highly suppressed in the SM. As a first measurement, we report several BF upper limits. D 0 mass peak is predominantly due to f(980) 0 D 0 and continuum. 384 M BB arXiv: [hep-ex]

August 20, 2007Charmless Hadronic B decays at BaBar21 B → K*  More pure-penguin or penguin dominated VV decay studies are desirable to resolve puzzles. K*ρ is the best candidate mode. Dominated by b  sg penguin diagram. Tree is doubly cabbibo-suppressed. K *0   is pure penguin. As in the K(892)*  mode, it is critical to understand the non- resonant  background and f 0 (980)K *. Use BF and f L from K *0   to reduce penguin error on       Beneke, et al, hep-ph/ ]

August 20, 2007Charmless Hadronic B decays at BaBar22 Strategy Simultaneous measurements of : Signal yield f L (longitudinal signal fraction) Charge Asymmetry Integrating over the  angle : Likelihood analysis over 7 variables :  E and m ES Reconstructed masses m V1 & m V2 Helicity angles cos  1 & cos  2 NNO N’(N) number of expected(observed) events. 232 M BB data samples

August 20, 2007Charmless Hadronic B decays at BaBar23 Strategy to identify signal Signal PDF PDFs for true and SCF(Self-cross feeding) respectively. Then, combine them with the fraction given by MC simulation. Two different PDFs for longitudinal and transverse-signal f L obs = N Lg / N Sig f L : Efficiency corrected

August 20, 2007Charmless Hadronic B decays at BaBar24 Efficiencies and SCF rate M ES ΔEΔE True-signal SCF signal M ES ΔEΔE K* +   Monte Carlo

August 20, 2007Charmless Hadronic B decays at BaBar25 Cut and Control Variables Signal-longitudinal, transverse, B 0 B 0, B + B -, and off- resonance after skim with (K* +  ) |M K  | < (150) , |M ,-0.771| < 375 (290) MeV/c < cos   < 0.98 (cos   > -0.5 (-0.9) for K + π 0 (π + π - ) |cos   | < 0.95 ) to get rid of slow neutral pions or low acceptance region. (Vertex fit   cut) M ES > 5.23 (5.25) GeV/c < ΔE < 0.12 GeV (|ΔE| < 0.1) For π 0, at least 50 (30) MeV and 0.01 <LAT< 0.6 photons used (0.12) < m γγ < 0.16 (0.15) GeV/c 2 For π + id, we veto electron, kaon and proton candidates. K + id used. M ES EE M K  M  cos   cos   NNO K* +   MC/Off-resonance

August 20, 2007Charmless Hadronic B decays at BaBar26 D 0 veto To veto B 0  D 0 (Kππ 0 )π 0 To veto B 0  D* 0 (Kππ 0 )π 0 From MC K* +   K* +   K+K+ K0sK0s Then, allow charm bg yield to float.

August 20, 2007Charmless Hadronic B decays at BaBar27 Charmless background K* +   K* +   K+K+ K0sK0s

August 20, 2007Charmless Hadronic B decays at BaBar28 ρ - K + π 0 / K* + π - π 0 Yield Estimate Estimated using extended M Kπ0 and M ππ0 region, [0.77,1.07]  [0.77,1.51] and [0.40,1.15]  [0.40,1.55] GeV/c 2. K* 0   sPlot Interference is not considered. Estimated as systematics. sPlot K* 0  

August 20, 2007Charmless Hadronic B decays at BaBar29 ρ - K + π 0 / K* + π - π 0 Yield Estimate (II) K* +   K+K+ K0sK0s Before adding ρ - K + π 0 After

August 20, 2007Charmless Hadronic B decays at BaBar30 B  K(892)*   232M BB PRL (2006)   K *+   K *0   K *0 f  (980)K *0   K *+ f  (980)K *+ Projection Plot

August 20, 2007Charmless Hadronic B decays at BaBar31 B  K*  PRL (2006) 1,2,3,4,5  contours (statistical only)

August 20, 2007Charmless Hadronic B decays at BaBar32 Belle’s K* 0    fb -1 

August 20, 2007Charmless Hadronic B decays at BaBar33 Conclusion f L measurements have been done in VV and VT decays and it’s a puzzle. Better theoretical explanation is needed. Hot news!! B  K*K*bar analysis is observed at BaBar. f L = 0.81±0.14 BF 5x  (arXiv: ) fLfL  K * (892)  0.49±0.06  K * (892)  0.51±0.05   K * (892) ±0.11   K * (892) ±0.13  K * 2 (1430) ±0.07

August 20, 2007Charmless Hadronic B decays at BaBar34 Feynman Diagram