BK pand photon spectrum at Belle

Heyoung YangSeoul National Universityfor Belle Collaboration

ICHEP2004

H.Y.G.Yang ICHEP2004-08-17 2

Introduction to bs(d)

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

H.Y.G.Yang ICHEP2004-08-17 3

Results on FCNC at Belle bs

First observation of BK1 First observation of B First observation of p photon spectrum

bd Search for B

H.Y.G.Yang ICHEP2004-08-17 4

bs(d) analysis tool Kinematic constraints

E = E*B ― E*

beam Mbc= (E*

beam)2 ― |P*B|2

Continuum suppression with event shape parameters B flight angle (cosB) Fisher discriminant

Particle ID with ACC/TOF/CDC

E Mbc

cosB Fisher

First Observation of BK1

with 140/fb

H.Y.G.Yang ICHEP2004-08-17 6

BK1 Known exclusive 2-body decay of bsprocess

BK*(892) (K*(892) K) BK2*(1430) (K2*(1430) K)

Possible 2-body decays : BK1 K1 axial vectors, mixing states of K1A & K1B

K1(1270) = K1A cos + K1B sin K1(1400) = K1A cos – K1B sin

H.Y.G.Yang ICHEP2004-08-17 7

BK1 Theoritical predictions (e.g) S.Veseli and M.G.Olsson PLB 367, 309(1996)

B[BK1(1270) =(1.200.44) 10-5

B[BK1(1400) =(0.580.26) 10-5

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

H.Y.G.Yang ICHEP2004-08-17 8

Inclusive BK B[B+K+ by Belle, 29.1/fb PRL 89(20

02) Reanalysis for / Ks0with 140/fb

318.222 B+K+ 67.49 B0K0

B[B+K+ ] = (2.50

0.18 0.22) 10-

5 20.4

B[B0K0 ] = (2.43

0.36 0.34) 10-

5 10.9 Firs

t Obse

rvation

H.Y.G.Yang ICHEP2004-08-17 9

BK1 MKdistribution for the search of K1(1270) or K1(1400)

K1(1270)K(42%) /K1(1400)K(3%) 0.6<M<0.8GeV K1(1270)K(16%) /K1(1400)K(94%)0.8<MK<1.0GeV

2D Unbinned fitting with Mbc& MK

Mbc

MK

Mbc

MKK1(1270)

K1(1400)

TotalK2*(1430)NR + b2s,K* feedcontinuum+BBbarK1 signals

0.6<M<0.8GeV 0.8<MK<1.0GeV

101.622 K1(1270) 22.726 K1(1400)

H.Y.G.Yang ICHEP2004-08-17 10

BK1

B[B+K1(1270)+ ] = (4.28 0.940.43) 10-5 9.2

B[B+K1(1400)+ ] <

1.4410-5 @ 90% CL 1.3

(1.0<MK<2.0 GeV )

First O

bservatio

n

First Observation of B

with 140/fb

H.Y.G.Yang ICHEP2004-08-17 12

B Ks can be used for the time-

dependent CP asymmetry study

Event reconstruction as +(Ks0)

45.011.0 BK

B[BK] = (6.9+1.7 +1.3-1.6 -1.0 ) 10-6 5.0

First O

bservatio

n

(MK<2.4 GeV)

H.Y.G.Yang ICHEP2004-08-17 13

B MK distribution for possible resonance Enhancement around MKGeV but not significant

K3*(1780) ?

1.6<MK<1.95 GeV

B[BK3*(1780)] <

34 10-6 @ 90% CL

First Observation of Bp

with 140/fb

H.Y.G.Yang ICHEP2004-08-17 15

Bp Radiative baryonic B decay, Bp

/ Bp

2D unbinned fitting with E & Mbc

34.17 B+p

Theoretical prediction:Theoretical prediction:* Pole Model* Pole Model: Phys.Lett. B533 (2002) B(B p) ~ 1.2x10-6

B(B pΣ0) ~ 2.9x10-9

*QCD counting rules*QCD counting rules: (hep-ph/0405283) B(B pΛ) ~ (1.2-2.4)x10-7

B(B pΣ0) ~ (2.8-6.5)x10-7

H.Y.G.Yang ICHEP2004-08-17 16

Bp

B[B+p] = (2.16

+0.58 -0.53

0.20) 10-6 8.6

B[B0p] < 3.3 10-6 @ 90% CL

pGeV/c2 for p (Mp 4.0 GeV/c2 for p

Details will be covered by M.-Z.Wang at next talk.

First O

bservation

Photon spectrum of bs

with 140/fb

H.Y.G.Yang ICHEP2004-08-17 18

Photon spectrum of bs Full inclusive reconstruction for only Espectrum Measure Eof highest mementum photon veto photons from 0 and 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, E > 2.0 GeV Babar : 54/fb, E > 2.1 GeV new result from Belle : 140/fb, E > 1.8 GeV

H.Y.G.Yang ICHEP2004-08-17 19

Photon spectrum of bs

Xs] = (3.550.32 )10-4

< E > = 2.2920.0260.034GeV<E2>-<E>2 = 0.0305 0.0074 0.0063GeV2

Data

After subtraction and efficiency correction

+0.30 +0.11 -0.31 -0.07 PRL93,061803(2004)

Search for B

with 253/fb

H.Y.G.Yang ICHEP2004-08-17 21

Search for B bd suppressed in SM by |Vtd/Vts|2

|Vtd/Vts|2 by B(B)/B(BK*)

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

H.Y.G.Yang ICHEP2004-08-17 22

Search for B Event reconstruction ()

/()/()

with special continuum suppression Fisher & cosB & z of B-ve

rtex LR(Likelihood Ratio) 2D optimization with L

R & QR(Quality of flavor tag)

LR

QR

signal

continuum

H.Y.G.Yang ICHEP2004-08-17 23

Search for B

BK* suppression by MKcut

suppression by helicity cut

BG BG

signal

H.Y.G.Yang ICHEP2004-08-17 24

Search for Bwith 253/fb For check of analysis method using BK*(892) study

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

H.Y.G.Yang ICHEP2004-08-17 25

Search for Bwith 253/fb

Total significance 1.9

Simultaneous unbinned fitting for assuming their isospin relations

H.Y.G.Yang ICHEP2004-08-17 26

Search for Bwith 253/fb B[B(] < 1.4 10-6

B[B+] < 2.2 10-6

B[B0] < 0.8 10-6

B[B] < 0.8 10-6

B[B(] / B[BK*] = 0.019

+0.012 -0.010 0.007 < 0.035

|Vtd/Vts| = 0.160.050.02(th)

< 0.22 @ 90% CL

( Form factor : Ali (2004) : 0.85 0.10 is used )

H.Y.G.Yang ICHEP2004-08-17 27

Summary First observations of

B+K1(1270)+/ inclusive B0K0 B p

Upper limits of B+K1(1400)+ BK3*(1780) B0p B / B |Vtd/Vts|

Measured photon spectrum of bs