BK1g, Khg, pLg, r/wg and photon spectrum at BelleHeyoung YangSeoul National Universityfor Belle CollaborationICHEP2004

ICHEP2004-08-17

Introduction to bs(d)gFCNC process forbidden at tree level in SM sensitive to New PhysicsB-factory experiments best experiment to measure FCNC e+e- collider experiment - good background suppresion with high Luminosity

ICHEP2004-08-17

Results on FCNC at BellebsgFirst observation of BK1g First observation of BKhgFirst observation of BpLgphoton spectrum

bdgSearch for Br/wg

ICHEP2004-08-17

bs(d)g analysis toolKinematic constraintsE = 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/CDCDEMbccosqBFisher

ICHEP2004-08-17

First Observation of BK1g with 140/fb

ICHEP2004-08-17

BK1gKnown exclusive 2-body decay of bsg processBK*(892) g (K*(892) Kp)BK2*(1430) g (K2*(1430) Kp)

Possible 2-body decays : BK1g K1 : axial vectors, mixing states of K1A & K1B K1(1270) = K1A cosq + K1B sinq K1(1400) = K1A cosq K1B sinqK1(1270) Kr (rpp) (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

BK1g Theoritical predictions (e.g) S.Veseli and M.G.Olsson PLB 367, 309(1996)B[BK1(1270) g] =(1.200.44) 10-5B[BK1(1400) g] =(0.580.26) 10-5

H.Y.Cheng and C.K.Chua PRD 69, 094007(2004)sensitive to their mixing angleB[BK1(1270) g] =(0.770.11) 10-5 (or (0.020.02) 10-5 )B[BK1(1400) g] =(0.080.04) 10-5 (or (0.800.12) 10-5 )

ICHEP2004-08-17

Inclusive BKppgB[B+K+p-p+g] =(2.40.5 )10-5 by Belle, 29.1/fb PRL 89(2002) Reanalysis for K+p-p+g / Ks0p-p+g with 140/fb318.222 B+K+p-p+g 67.49 B0K0p-p+g +0.4-0.2First Observation

ICHEP2004-08-17

BK1g MKpp distribution for the search of K1(1270) or K1(1400)K1(1270)Kr (42%) / K1(1400)Kr (3%) 0.6

BK1g

(1.0

First Observation of BKhgwith 140/fb

ICHEP2004-08-17

BKhgKshg can be used for the time-dependent CP asymmetry study

Event reconstruction as K+(Ks0)hg , (hgg, hp+p-p0 )45.011.0 BKhgFirst Observation(MKh

BKhgMKh distribution for possible resonanceEnhancement around MKh 1.8GeV but not significantK3*(1780) ?1.6

First Observation of BpLgwith 140/fb

ICHEP2004-08-17

BpLgRadiative baryonic B decay, BpLg / BpS0g

2D unbinned fitting with E & Mbc 34.17 B+pLg Theoretical prediction:* Pole Model: Phys.Lett. B533 (2002) B(B pg ) ~ 1.2x10-6 B(B p0g) ~ 2.9x10-9*QCD counting rules: (hep-ph/0405283) B(B pg) ~ (1.2-2.4)x10-7 B(B p0g) ~ (2.8-6.5)x10-7

ICHEP2004-08-17

BpLg(MpL < 2.4 GeV/c2 for B+pLg) (MpL

Photon spectrum of bsgwith 140/fb

ICHEP2004-08-17

Photon spectrum of bsgFull inclusive reconstruction for only Eg spectrumMeasure Eg of highest mementum photonveto photons from p0 and happly 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 GeVBabar : 54/fb, Eg > 2.1 GeVnew result from Belle : 140/fb, Eg > 1.8 GeV

ICHEP2004-08-17

Photon spectrum of bsgB [BXsg] = (3.550.32 )10-4 < E > = 2.2920.0260.034 GeV-2 = 0.0305 0.0074 0.0063 GeV2Data After subtraction and efficiency correction+0.30 +0.11 -0.31 -0.07PRL93,061803(2004)

ICHEP2004-08-17

Search for Br/wgwith 253/fb

ICHEP2004-08-17

Search for Br/wgbdg suppressed in SM by |Vtd/Vts|2|Vtd/Vts|2 by B(Br(w)g)/B(BK*g)

large direct CP violation is predicted in bdg Ali and Parkhomenko, Eur.Phys.J. C23 (2002) 89-112 Bosch and Buchalla, Nucl.Phys. B621 (2002) 459-478

ICHEP2004-08-17

Search for Br/wgEvent reconstruction r0(p+p-)g/r+(p+p0)g/w(p+p-p0)g

with special continuum suppressionFisher & cosqB & Dz of B-vertex LR(Likelihood Ratio)2D optimization with LR & QR(Quality of flavor tag) LRQRsignalcontinuum

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Search for Br/wgBK*g suppression by MKp cut B rp0 suppression by helicity cut BGBGsignal

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Search for Br/wg with 253/fbFor check of analysis method using BK*(892)g study

B[BK*(892)g] = (37.2 1.8) 10-6 good agreement with World Average

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Search for Br/wg with 253/fb B+r+g B0r0g BwgTotal significance 1.9 s Simultaneous unbinned fitting for r+g / r0g / wg assuming their isospin relations

ICHEP2004-08-17

Search for Br/wg with 253/fb

ICHEP2004-08-17

SummaryFirst observations of B+K1(1270)+g / inclusive B0K0p+p-gBKhgB+pLgUpper limits ofB+K1(1400)+gBK3*(1780)gB0pS0gBrg / Bwg|Vtd/Vts|Measured photon spectrum of bsg

ICHEP2004-08-17