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Aug.20, 2004 Recent results from Belle 1
Recent Results from Belle
Shiro Suzuki (Saga University)
PASCOS04 / Pran Nath Fest, Aug 20, 2004 Northeastern University, Boston, MA
Aug.20, 2004 Recent results from Belle 2
Outline
Belle / KEKB
CPV “Standard” sin21 as the SM reference TCPV in b s penguin dominated decays Direct CPV
Rare processes FCNC ( b s, sll) via EW penguin
Aug.20, 2004 Recent results from Belle 3
~1 km in diameter
Mt. Tsukuba
KEKBBelle
8 GeV e8 GeV e-- x 3.5 GeV e x 3.5 GeV e++
@ 1.2A x 1.6A@ 1.2A x 1.6ALLpeakpeak = 1.39 x 10 = 1.39 x 1034 34 secsec-1-1cmcm-2 -2
11mrad crossing
281 fb-1274M BB253 fb-1 on Y(4S)
28 fb-1 below Y(4S)
KEKB Collider
Aug.20, 2004 Recent results from Belle 4
IHEP, Moscow IHEP, ViennaITEPKanagawa U.KEKKorea U.Krakow Inst. of Nucl. Phys.Kyoto U. Kyungpook Nat’l U. U. of Lausanne U. of Ljubljana Jozef Stefan Inst.U. of Maribor
Aomori U.BINPChiba U.Chonnam Nat’l U.Chuo U.U. of CincinnatiEwha Womans U.Frankfurt U.Gyeongsang Nat’l U.U. of HawaiiHiroshima Tech.IHEP, Beijing
U. of MelbourneNagoya U.Nara Women’s U.National Central U.Nat’l Kaoshiung Normal U.Nat’l Lien-Ho Inst. of Tech.Nat’l Taiwan U.Nihon Dental CollegeNiigata U.Osaka U.Osaka City U.Panjab U.Peking U.Princeton U.RikenSaga U.USTC
Seoul National U.Shinshu U.Sungkyunkwan U.U. of SydneyTata InstituteToho U.Tohoku U.Tohuku Gakuin U.U. of TokyoTokyo Inst. of Tech.Tokyo Metropolitan U.Tokyo U. of A and T.Toyama Nat’l CollegeU. of TsukubaUtkal U.VPIYonsei U.
13 countries, institutes, 400 members
The Belle Collaboration
Aug.20, 2004 Recent results from Belle 5
/ KL detection 14/15 lyr. RPC+Fe
Central Drift Chamber small cell +He/C2H5
CsI(Tl) 16X0
Aerogel Cherenkov cnt. n=1.015~1.030
Si vtx. det. 3(4) lyr. DSSD
TOF conter
SC solenoid 1.5T
8 GeV e
3.5 GeV e
Belle Detector
Aug.20, 2004 Recent results from Belle 6
b
s
d
VVV
VVV
VVV
b
s
d
tbtstd
cbcscd
ubusud
'
'
'
2
2
)1(
2/
)(2/
AiA
A
iA
CPV: due to a complex phase in the quark mixing matrix
CKM matrix
Wolfenstein representation
1
2
3
Vtd Vtb
Vcd Vcb
Vud Vub*
*
*
Unitaritytriangle
Kobayashi-Maskawa Scheme
observablesWeak eigenstate
Mass eigenstate
Aug.20, 2004 Recent results from Belle 7
Time dependent CP Violation (TCPV)
For single decay diagram as above,
||=1 (i.e. A=0, no DCPV), S = Im 1
2
, sinSimil
si2
a
n
r ,
2
ly
bb ccd
uudsqq
1ex) sin 2 fSb ccs
General description
2
2
0
02
2I
1=
m
1
1 CP d
f
CP d
f Bq
p f BS A
whereMixing induced CPV
Direct CPV0 0
0 0
( ) ( ) sin( ) cos( )
( ) ( )d CP d CP
CPd CP d CP
B f B fA m t m t
B f B fS A
Aug.20, 2004 Recent results from Belle 8
5417 events @ 140 fb1
sin21=0.7280.0560.023
ccs1.007 ± 0.041 ±
consistent with no direct CPV
Good Tag
Poor Tag
Good agreement with SM SM Reference
sin21 by b →ccs processes
now issue is to measure “sin21” with different decay processes such as ccd, sqq .
WA = 0.736±0.049
Aug.20, 2004 Recent results from Belle 9
CP Violation in penguin dominated decays
SM Penguin : same CPV phase as ccs
+ New Physics with different phase
+
CPV may be different : Sbs≠Sbc, A≠0 ⇒
hint of new physics Ex) B0 Ks 7.8 1.1 (×106)* theoretically clean but Br small B0 ’Ks 65.2 6.0 B0 K+KKs 25.2 2.7
b→sqq: Possible contribution of new physics → new phase
Aug.20, 2004 Recent results from Belle 10
Fit sin21
B0 KS B0 KKKSB0 ’KS
fS
A
09.011.050.096.0
07.029.015.0
18.000.005.026.051.0
04.016.017.0
05.027.043.0
04.016.001.0
[PRL 91, 261602 (2003)]
“sin21” 3.5 away from SM !
=b→s modes in 2003
⇒ Needs measurements w/ larger data sample & additional modes
140fb
Aug.20, 2004 Recent results from Belle 11
Validity checks of 250fb-1 sample SM control sample : J/K0
Data set I (140fb) S = 0.696±0.061 A = 0.011±0.043
Data set II (110fb) S = 0.630±0.069 A = 0.035±0.044
Life time in J/K0, K+, K0 Null asymmetry in D*l , K+
⇒ overall check of resol. func. & flavor tagging
Data set I
Data set II
Good tags
Good tags
Aug.20, 2004 Recent results from Belle 12
B → K0
includes Ks (Nsig=13 5)
pB*
274M BB
KS
Nsig=139 14purity 0.63
Nsig= 36 15
KL
purity 0.17
Aug.20, 2004 Recent results from Belle 13
B → K0 CPV result
KS + KL
: S (K0) = +0.06 ±0.33 ±0.09
A (K0) = +0.08 ±0.22 ±0.09 “sin21” ~2.2 away from SM
KS + KL
: S (K0) = +0.06 ±0.33 ±0.09
A (K0) = +0.08 ±0.22 ±0.09 “sin21” ~2.2 away from SM
274M BB
Poor tags
Good tags
preliminary
S = 0.736fit
Aug.20, 2004 Recent results from Belle 14
’KS KKKS
Nsig=512 27purity 0.61
Nsig=399 28purity 0.56
S = +0.65 0.18 0.04 S = +0.49 0.18 0.04 ( ) A = 0.19 0.11 0.05 A = 0.08 0.12 0.07
CP=+1: 1.03 0.15 0.05
“sin21”
Raw
Asy
mm
etry
Good tags Good tags
S = 0.736fit
0.170.00
B0 → ’KS & K+KKS
(~0.5@SM) (~1.0@SM)
high statistics modes’
( , )
Aug.20, 2004 Recent results from Belle 15
KS
New modes !
Nsig=31 7purity 0.56 Nsig=102 18
purity 0.58
f0(980)KS
S = +0.75 0.64 S = 0.47 0.41 0.08 A = 0.26 0.48 0.15 A = 0.39 0.27 0.08
“sin21”
Raw
Asy
mm
etry
Good tags
S = 0.736fit
0.130.16
Good tags
B0 → KS & f0(980)KS
(~0@SM) (~2.9@SM)
Aug.20, 2004 Recent results from Belle 16
Summary of b→sqq TCPV
A : consistent with 0
2.4
“sin2”
Aug.20, 2004 Recent results from Belle 17
Direct CPV in B →K
Another essence of KM scheme – existence of direct CPV More than two diagrams should contribute
-- With different CP and strong phase
CPV in decay – partial rate asymmetry
( ) ( )
( ) ( )CP
N B f N B f
N B fA
N B f
Penguin d
b
d
u
uW
B0d -
Vus
Vub
Tree
B0dd d
u
u
W
g
-
VtsVtb
ts
s
b
Aug.20, 2004 Recent results from Belle 18
Evidence for direct CPV in B0→K+
Signal yield: 2139±53
ACP (K) 0.101±0.025±0.005 ( 3.9 significance )
2nd evidence ofDCPV at Belle
Continuum BG elimi-nated by modified F-W
K/ ID efficiency and fake rates determined by D*+→D0, D0→K sample
_B0 K B0 K
274M BB
Submitted to PRL
Aug.20, 2004 Recent results from Belle 19
ACP for B+→K+
Hint of ACP(K+)≠ACP(K+0) 2.4 away
Large EW penguin contribution ? New physics ?
K+ Signal yield : 728±34 ACP(K+
0.04±0.05±0.02
B
K
274M BB, New
Aug.20, 2004 Recent results from Belle 20
Observation of B0 00Observation of B0 00274M BB, New
B = (2.32 ) x 10-6 Signal: 82 16 (6.0)
ACP = 0.43 0.51
uses same Flavor-tagging as TCPV analysis
1st measurement !
Mbc
0.410.48
0.220.18
0.170.16
Key mode for 2 in B→ CPV isospin analysis
Aug.20, 2004 Recent results from Belle 21
Radiative and EW Penguins
Br(b→s) ≈ 3.5×10
Br(b→sl+l≈ em×Br(b→s) ≈ 10
New particle (via loops) may make appreciable contribution to decay rates and/or asymmetries.
Good testing ground of
SM and beyond SM.
b→s, sl+l decays proceed via FCNC Box and penguin diagrams
b→s
b→sl+l
Aug.20, 2004 Recent results from Belle 22
B→ K(*)l+l results274M BB
Updated with 274M BB
Preliminary
79 10signals
82 11signals
0.75 70.70
*
2.3 72.2
( )
(5.50 0.27 0.02) 10 (11.0 )
( )
(16.5 0.9 0.4) 10 (10.1 )
B Kl l
B K l l
B
B
Aug.20, 2004 Recent results from Belle 23
( / 2) ( / 2)
( / 2) ( / 2)Bl Bl
FB
Bl Bl
A
AFB in K*ll provides information on sign of Wilson coef. ⇒ sensitive to NP that may not be seen in bs
PreliminaryFirst look !
K*
B→ K(*)l+l FB Asymmetry
Aug.20, 2004 Recent results from Belle 24
SummaryBased on 253 fb data sample TCPV of b → s penguin processes are measured in va
rious processes. Updated “sin21” in K0 is +0.06 ±0.33 ±0.09
~2.2 away from SM b→s average : +0.43 ± ~2.4 away from SM.
Evidence of DCPV in B0→K+ is observed Hint of ACP(K) ≠ACP(K)
First look at B K*ll AFB is made.
0.130.11