neue resultate vom belle experiment mainz g.leder 17.november 2004 das belle experiment das...

Neue Resultate vom BELLE Experiment Mainz G.Leder 17.November 2004

Das BELLE Experiment

• Das Experiment

• B-Physik

• Überblick über neueste Resultate

Gerhard LEDER Hephy ÖAW-Wien

~1 km in diameter

Mt. Tsukuba

KEKBBelle

KEK 　高エネルギTokyo 東京


Lpeak=1.4 x1034cm-2sec-1

design=1034cm-2secKEKB Collidere-

8GeV

e+

3.5GeV

= 0.425

B-Factory(on the 4s resonance)

B-Factory(on the 4s resonance)

BBthreshold

BBthreshold


Kontinuierliche Injection[CERN courier Jan/Feb 2004]Kein Grund, Run zu unterbrechen

Immer bei ~max. Strömen, Luminosität~30% more L dt

both KEKB & PEP-II

HER current

LER current

continuous injection (new)normal injection (old)

Luminosity

0 12 24Time

~1 fb-1/day ! (~1x106 BB)-


SVD

Der BELLE Detektor


Unterschied SVD1.6 und SVD2.0Rbeampipe

15 mm

Rlayer 1

20 mm

Routside

88 mm

6+12+18+18=54

LaddersSVD2

Rbeampipe

20 mm

Rlayer 1

30 mm

Routside

60 mm

8+10+14=32

Ladders SVD1


Wiener R/O & Trigger Elektronik

R-PHI Trigger

R-Z Trigger

24 input OR and

analog signal input from

VATA

2 x 18 FADCTF


B Zerfälle und das Standard Modell

Electro-weak

Hadrons

Quark levelQuark level

Final stateFinal state QCD/LatticeNew Resonances

QCD/LatticeNew Resonances

b-quark: Heavy variety of decay modes

Reiches Feld für fundamentale SM Parameter

1

2

3

Vtd Vtb

Vcd Vcb

Vud Vub*

*

*


B Zerfälle und “Neue” Physik

Experimentalmeasurements SM predictionsagree?

Deeper understandingDeeper understandingNew Physics ?New Physics ?

YesNo

Key point: ANP ~ ASM (small/forbidden)

b t s,dg,,Z

WPenguin

b x s,d+

New particle, Phase


Methods to extract B signal yield:1) Cut on MB and fit to ECut on E and fit to MB

3) Double dimensional fit to MB and E distribution

4) If B->P1P2P3: cut Eand MB

box and look at resonant structures in M(P1P2) mass distribution.

Prozedur, um B Signal zu extrahieren

Two almost independent variables MB andE can be used to select B meson signal:

MB = (Ebeam)2 – ( Pi)2

E = Ei - Ebeam

*

*

Verwende spezielle Kinematik des Y(4S)


Continuums Unterdrückung

e+

e-

e+

e-

qq

Signal B

Other B

Dominanter Untergrund für seltene Zerfälle:

Continuum

Jet-like

BB

sphärisch

e+e qq “continuum” (~3x BB)

To suppress: use event shape variables

continuum

Y (4S)


Continuums Unterdrückung

To separate spherical BB events from jet-like continuum events, topological variables are used:

1) Second Fox-Wolfram moment2) Super Fox-Wolfram (six modified Fox-Wolfram

moments, Fisher discriminant)3) Angle between B meson and beam axis direction4) Angle between thrusts of selected B meson particles and

all other particles in event

Likelihood ratio includes all info.


Die Standard Modell Physik bei BELLE

selbstkonsistent falls SM korrekt

Vtb*Vtd

Vcb*Vcd

Unitaritäts Dreieck

Vub*Vud

Vcb*Vcd

Vtb*Vtd

Vcb*Vcd

+ 1 + = 0

i i

{i=1,k=3}: Vub*Vud+Vcb*Vcd+Vtb*Vtd = 0 d s b

u Vud Vus Vub

c Vcd Vcs Vcb

t Vtd Vts Vtb

CKM-Matrix

1

i

0

BB00->ππ->ππBB00->->ππ

BB00->J/->J/KKss

BB00->->KKss

BB00->D->D((**) ) DD((**))BB00-> D*π-> D*πBB00->D*->D*B->DB->DCPCPKK

Vub*Vud

Vcb*Vcd

1

2

3


Penguin d

b

d

s/d

u

u

W

B0d -

+

Vus/d

Vub

Tree

• Simplest charmless rare decay modes• Tree - Penguin interference Direct CP Violation

Key prediction of Kobayashi-Maskawa model

Key prediction of Kobayashi-Maskawa model

Understanding of Penguin

_ _ (B f ) (B f ) _ _ (B f ) (B f )

ACP =

Anomaly (New Physics)

B0d

d

b

du

u

W

g +

-

Vts/dVtb

ts/d

Direkte CP-Verletzung:B K/


ACP(B0 K)

Evidenz für DCPV bei Belle auch bei [A() 3.2]

ACP = -0.101 0.025 0.005 [PID efficiency bias correction: A = -0.01 0.004]

275M BB Neu

3.9 significance

[submitted to PRL]

B0 K _B0 K

Signal: 2139 53


Time-Dependent CP Asymmetry

0 0

0 0

( ) ( )( )

( ) ( )

sin cos

CPCP

CPCP

B fB fCP

B fB f

d d

t tA t

t t

m t m tS A

2

2

2

2Im( )

1

1)

1, ( CAS

2 ( )

( )Mi CP

CP

A B fe

A B f

•The CP violation manifests itself in proper-time difference distributions of two B meson decays.

•The time-dependent CP asymmetry ACP is:

•Standard Model prediction: Sccs = sin21, Accs = 0

Ssss = sin21, Asss = small


• Rekonstruiere B J/K0 Zerfälle• Messe Eigenzeit Differenz: t • Bestimme flavor von Btag

• Berechne CP Asymmetry aus beiden t Verteilungen

Prinzip der Messung

e ee: 8.0 GeVe: 3.5 GeV

BCP

z

Btag

(4S) ~ 0.425

fCP (J/K0)fCP (J/K0)

z cB ~ 200 m

Flavor tagFlavor tag( )

z

ct

( )

z

ct


Prinzip der 1-Messung mit B J/Ks

t z/(cβγ)

Flavor-tag decay(B0 or B0 ?)

J/

KS

B - B

B + B

ee

more B’s

more B’s

zt=0

fCP


sin21 mit 152106 BB Paaren

4347 signal events @ 152106 BB

1sin 2 0.728 0.056 0.023 1sin 2 0.728 0.056 0.023

1.007 0.041 0.033 consistent with no direct CPV

poor flavor tag

good flavor tag

K. Abe et al. [Belle collaboration], BELLE-CONF-0436.

Decay modes used:• J/KS(), J/KS(20), (2S)KS, c1KS, cKS

• J/K*(KS0)• J/KL


Voriger Detektor

(152106 BB)

Neuer Detektor

(122106 BB)

Lebensdauer und Mixing mit neuem DetektorParameter fit results

(with new detector only)

1.518 0.012

0B

B

dm

0B

B

dm

1.534 0.008 0.010 [ps]

[ps]

[ps1]

Belle preliminary

Belle preliminary

Belle preliminary

Belle preliminary

New detector resolution is well understood.Previous data sets and fitting function for them are unchanged.

1.652 0.014

0.516 0.007

1.635 0.011 0.011

0.511 0.005 0.006


CP violation “same” as J/Kswithin the Standard Model (SM)Penguin~O(2), Tree~O(4)deviation = O(1)%

•Indirect CP Violation : Mixing und/oder•Tree - Penguin interference sin21(bsqq) = 0.41 0.07

sin21(bccs) = 0.726 0.037B0

B0 B0

Vc

b

Vt

b

V*

V*Vtb

V*2

td

td

td

J/

J/

KS

KS

Vc

b


B0 K0

Similar to J/KL recon.+ sophisticated continuum suppression

includes Ks (Nsig=13 5)

KS

Nsig=139 14purity 0.63

pB*

Nsig= 36 15

KL

purity 0.17

275M BB

[hep-ex/0409049]


B → K0 CPV Resultat

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

275M BB

Poor tags

Good tags

S = 0.736fit

[hep-ex/0409049]


BABAR Resultate für B0 K0

227M BB pairs 227M BB pairs

BABAR-CONF 04/033

0SK

0

0

0.070 50 0.25 0.040 00 0.23 0 05

CP K

K

S .

C . .

0LK

0

98 18 events1.05 0.51

LKS

0 0LB K

BBAABBARARBBAABBARAR

0

114 12 events0.29 0.31

SKS

0 0SB K


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

Raw

Asy

mm

etry

Good tags

S = 0.736fit

0.130.16

Good tags

B0 → KS & f0(980)KS

(~0@SM) (~2.9@SM)

“sin21”


sin21 from bs penguins at FPCP04

sin21(bsqq) = 0.41 0.07 sin21(bccs) = 0.726 0.037

CL = 0.00012 (3.8)


„Neue“ Physik bei B K0 ?• B Ks theoretisch verstanden• A = 0.08 ± 0.22 ± 0.09• sin21eff = 0.06 ± 0.22 ±0.09• 2,2 Abweichung von „SM“

SM predicts same CPV in b ccs and sqq.

SM predicts same CPV in b ccs and sqq.

New physics may deviate CPV in b ccs from sqq New physics may deviate CPV in b ccs from sqq

+

SM penguinSM penguin New process with different CP phase

New process with different CP phase

sin21(bsqq) = 0.41 0.07 sin21(bccs) = 0.726 0.037

CL = 0.00012 (3.8)


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

Zukünftige Untersuchungen:


X(3872) Produktion in B Zerfällen

35±7 eventsM=3872.0±0.8 MeV<2.3MeV (90%)

Recently, Belle observed the X(3872) in B+->X(3872) K+ decay, with X(3872)->J/+- (confirmed by CDF, D0 and BaBar).

M(J/+-) – M(J/)

’

X(3872)

M(J/ +-)

Br(B-KX3872) Br(X3872J/)

Br(B-K’) Br(’J/) = 0.063 ± 0.012 ± 0.007


Charmonium Spektroskopie

hc

’

c’’

c

J/

c0

c1

c2

hc’

c1’c2

Isospin 0++allowedIsospin 1--violating

Decay to J/ +-

< 1 MeV/c2

X(3872)

2MD

MD*+MD


Studie der X(3872) Produktion in B Zerfällen

Xc2(XJ/ = 0.42 ± 0.45 ± 0.23 <1.1 (90%CL)

Search for B X(3872)K decay,

with X(3872)c2

Search for B X(3872)K decay,

with X(3872)J

XJ/(XJ/ =

0.22 ± 0.12 ± 0.06 <0.40 (90%CL)

MB E

MB MX E

X

Helicity angle: if Jp=1+- (hc’), sin2 angular distribution is expected. ruled out by data.

|cos |

152x106 BB pairs


Studie vom B+ X(3872) K+ Zerfall, X(3872) J/+-0

These events arealmost pure signal

Nevt=10.0 ± 3.6S/N = 5/1

Signif = 5.8

events with M(3)>0.75 GeV

274x106 BB pairs

| M(J/+-) – 3872. | < 12 MeV/c2

Events within B signal region and mass interval:

XJ/(XJ/ = 0.8 ± 0.3 (stat) ± 0.1(syst)

Assuming events with M(3) > 0.75 as J/ :

It provides support for DD* molecular interpretation of X(3872).


Welcher Zustand ist X(3872)?

Keine guten cc Kandidaten für X(3872):_

c”

hc’

c1’

2

c2

3

M too low and too small

angular dist’n rules out 1

J/ way too small

c too small; (PRL 93, 2003)

c should dominateJ/

c& DD) too small

- Isospin violating decays to J/ +-


Neue Charmonium Resonanz ? Interpretation:• Masse gerade an der D0D*0 Schwelle• lose gebundenes “molecular charmonium”, oder ein (13D2) Zustand?

Ersteres in der Literatur diskutiert seit 1975:– ausgelöst durch komplizierte Struktur von (e+e- ->hadrons) bei SPEAR

• M. Bander, G.L. Shaw, P. Thomas, PRL 36, 695 (1976)• M.B. Voloshin, L.B. Okun JETP Lett. 23, (1976), Pisma Zh.Eksp.Teor.Fiz.23, 369 (1976) • A.De Rujula, H.Georgi, S.L.Glashow, PRL 38 (1977)

– WW beschrieben durch -Austausch gibt attraktive Kraft für DD*, BB*• N.A. Tornqvist, PRL 67, 556 (1991), Z.Phys. C61, 525(1994)

• A.V. Manohar, M.B. Wise,Nucl.Phys. B339, 17(1993)

Qq

Qq

D0D*0

Molekül

Diquark Model(Qq) are colored

Lose Bindung

Ältere Ideen:

Decays to (QQ)+(light mesons) via quarkrearrangement which suppresses the width.

Stärkere Bindung

Q Qq q


Zusammenfassung (1)

SM bisher überraschend selbst in Details erfüllt!Bestimmung der CKM-Matrix-Elemente im SM

Indirekte CP-Verletzung A(t) bestimmt mit hoher Präzision

sin21(bccs) = 0.726 0.037

Grosse Anstrengung auch die beiden anderen Winkel zu messen(2 und 3)Außerdem „Seitenlängen“ des Dreiecks: md und ms, sowieVub/Vcb etc.

sin21(bsqq) = 0.41 0.07 Bedeutet anderer Wert(3.8 schon „neue Physik“ oder„nur“ Penguin-Beitrag ?


Zusammenfassung (2)

Beträchtliche Direkte CP-Verletzung (3.9 )

ACP (B0 K+ -) = -0.101 0.025 0.005

Asymmetrie Materie-Antimaterie im Universum ?

Molekül D*0D0 = 4 Quarkzustand oder konventionelle Erklärung?

Neues Gebiet: Ds- Spektroskopie etc.

BELLE ist bei vielen Gebieten an vorderster Front:

SUPERBELLE mit höherer Luminosität

neue resultate vom belle experiment mainz g.leder 17.november 2004 das belle experiment das...

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