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B K 1 g, Khg, p Lg, r/wg and photon spectrum at Belle

B K 1 g, Khg, p Lg, r/wg and photon spectrum at Belle. Heyoung Yang Seoul National University for Belle Collaboration ICHEP2004. Introduction to b s(d) g. FCNC process forbidden at tree level in SM  sensitive to New Physics B-factory experiments best experiment to measure FCNC

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B K 1 g, Khg, p Lg, r/wg and photon spectrum at Belle

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  1. BK1g, Khg, pLg, r/wg and photon spectrum at Belle Heyoung Yang Seoul National University for Belle Collaboration ICHEP2004

  2. Introduction to bs(d)g • FCNC process forbidden at tree level in SM  sensitive to New Physics • B-factory experiments best experiment to measure FCNC e+e- collider experiment - good background suppresion with high Luminosity ICHEP2004-08-17

  3. Results on FCNC at Belle • bsg • First observation of BK1g • First observation of BKhg • First observation of BpLg • photon spectrum • bdg • Search for Br/wg ICHEP2004-08-17

  4. bs(d)g analysis tool DE Mbc • Kinematic constraints • E = E*B ― E*beam • Mbc= (E*beam)2 ― |P*B|2 • Continuum suppression with event shape parameters • B flight angle (cosqB) • Fisher discriminant • Particle ID with ACC/TOF/CDC cosqB Fisher ICHEP2004-08-17

  5. First Observation of BK1g with 140/fb

  6. BK1g • Known exclusive 2-body decay of bsg process • BK*(892) g (K*(892) Kp) • BK2*(1430) g (K2*(1430) Kp) • Possible 2-body decays : BK1g • K1: axial vectors, mixing states of K1A & K1B K1(1270) = K1A cosq + K1B sinq K1(1400) = K1A cosq – K1B sinq • K1(1270) Kr (rpp) (42%) • K*p (K*Kp) (16%) • K0*p (K0*Kp) (48%) • Kpp ( 83%) K1(1400)K*p (K*Kp) (94%) Kpp ( 94%) ICHEP2004-08-17

  7. BK1g • Theoritical predictions (e.g) S.Veseli and M.G.Olsson PLB 367, 309(1996) • B[BK1(1270) g] =(1.200.44) 10-5 • B[BK1(1400) g] =(0.580.26) 10-5 H.Y.Cheng and C.K.Chua PRD 69, 094007(2004) • sensitive to their mixing angle • B[BK1(1270) g] =(0.770.11) 10-5(or (0.020.02) 10-5 ) • B[BK1(1400) g] =(0.080.04) 10-5 (or (0.800.12) 10-5 ) ICHEP2004-08-17

  8. Inclusive BKppg +0.4 -0.2 • B[B+K+p-p+g] =(2.40.5 )10-5 by Belle, 29.1/fb PRL 89(2002) • Reanalysis for K+p-p+g / Ks0p-p+g with 140/fb 318.222 B+K+p-p+g 67.49 B0K0p-p+g First Observation ICHEP2004-08-17

  9. BK1g • MKpp distribution for the search of K1(1270) or K1(1400) • K1(1270)Kr (42%) /K1(1400)Kr (3%) 0.6<Mpp<0.8GeV • K1(1270)K*p (16%) /K1(1400)K*p (94%) 0.8<MKp<1.0GeV • 2D Unbinned fitting with Mbc& MKpp 0.6<Mpp<0.8GeV 0.8<MKp<1.0GeV Mbc Mbc Total K2*(1430) NR + b2s,K* feed continuum+BBbar K1 signals K1(1270) MKpp MKpp K1(1400) 101.622 K1(1270) 22.726 K1(1400) ICHEP2004-08-17

  10. BK1g FirstObservation (1.0<MKpp<2.0 GeV ) ICHEP2004-08-17

  11. First Observation of BKhg with 140/fb

  12. BKhg • Kshg can be used for the time-dependent CP asymmetry study • Event reconstruction as K+(Ks0)hg , (hgg, hp+p-p0 ) 45.011.0 BKhg First Observation (MKh<2.4 GeV) ICHEP2004-08-17

  13. BKhg • MKh distribution for possible resonance • Enhancement around MKh 1.8GeV but not significant K3*(1780) ? 1.6<MKh<1.95 GeV ICHEP2004-08-17

  14. First Observation of BpLg with 140/fb

  15. BpLg • Radiative baryonic B decay, BpLg / BpS0g • 2D unbinned fitting with E & Mbc Theoretical prediction: * Pole Model: Phys.Lett. B533 (2002) B(B pΛg) ~ 1.2x10-6 B(B pΣ0g) ~ 2.9x10-9 *QCD counting rules: (hep-ph/0405283) B(B pΛg) ~ (1.2-2.4)x10-7 B(B pΣ0g) ~ (2.8-6.5)x10-7 34.17 B+pLg ICHEP2004-08-17

  16. BpLg First Observation Details will be covered by M.-Z.Wang at next talk. (MpL < 2.4 GeV/c2 for B+pLg) (MpL<4.0 GeV/c2 for B0pS0g) ICHEP2004-08-17

  17. Photon spectrum of bsg with 140/fb

  18. Photon spectrum of bsg • Full inclusive reconstruction for only Egspectrum • Measure Eg of highest mementum photon • veto photons from p0 and h • apply event shape cuts to suppress continuum b.g. • cut optimized by using 15/fb off-resonance data • Photon energy spectrum measurements: • CLEO : 9/fb, Eg > 2.0 GeV • Babar : 54/fb, Eg > 2.1 GeV • new result from Belle : 140/fb, Eg > 1.8 GeV ICHEP2004-08-17

  19. Photon spectrum of bsg After subtraction and efficiency correction Data B [BXsg] = (3.550.32 )10-4 < E > = 2.2920.0260.034GeV <E2>-<E>2 = 0.0305 0.0074 0.0063GeV2 +0.30 +0.11 -0.31 -0.07 PRL93,061803(2004) ICHEP2004-08-17

  20. Search for Br/wg with 253/fb

  21. Search for Br/wg • bdg suppressed in SM by |Vtd/Vts|2 • |Vtd/Vts|2 by B(Br(w)g)/B(BK*g) • large direct CP violation is predicted in bdg Ali and Parkhomenko, Eur.Phys.J. C23 (2002) 89-112 Bosch and Buchalla, Nucl.Phys. B621 (2002) 459-478 ICHEP2004-08-17

  22. Search for Br/wg signal LR • Event reconstruction r0(p+p-)g/r+(p+p0)g/w(p+p-p0)g • with special continuum suppression • Fisher & cosqB & Dz of B-vertex LR(Likelihood Ratio) • 2D optimization with LR & QR(Quality of flavor tag) continuum QR ICHEP2004-08-17

  23. Search for Br/wg B rp0 suppression by helicity cut BK*g suppression by MKp cut BG BG signal ICHEP2004-08-17

  24. Search for Br/wg with 253/fb • For check of analysis method using BK*(892)g study • B[BK*(892)g] = (37.2  1.8) 10-6  good agreement with World Average ICHEP2004-08-17

  25. Search for Br/wg with 253/fb Simultaneous unbinned fitting for r+g / r0g / wg assuming their isospin relations Total significance 1.9 s B+r+g B0r0g Bwg ICHEP2004-08-17

  26. Search for Br/wg with 253/fb ICHEP2004-08-17

  27. Summary • First observations of • B+K1(1270)+g / inclusive B0K0p+p-g • BKhg • B+pLg • Upper limits of • B+K1(1400)+g • BK3*(1780)g • B0pS0g • Brg / Bwg • |Vtd/Vts| • Measured photon spectrum of bsg ICHEP2004-08-17

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