Sep 11, 2006SLUO Anual Meeting 20061 Search for Super-Penguins: CP Violation in B 0 ->K+K-K 0 D. Dujmic, SLAC For BABAR Collaboration D. Dujmic, SLAC For

Sep 11, 2006 SLUO Anual Meeting 2006 1

Search for Super-Penguins:CP Violation in B0->K+K-K0

Search for Super-Penguins:CP Violation in B0->K+K-K0

D. Dujmic, SLACFor BABAR Collaboration

D. Dujmic, SLACFor BABAR Collaboration

Special thanks to: G. Cavoto, M. Krishnamurthy, E. Di Marco, M.Pierini, A.Roodman, S.Spanier, J.Thompson

SMrules


CP Violation in SMCP Violation in SMCKM picture of charged weak currents:

But amount of CP violation too small:- observation:

- area of unitarity triangle:

p=u,c,t

q=d’,s’,b’

W ±Vpq

10

BB

BB

γ

B 106NN

NN

nn

10TJ

NN

NN :CKM 20

12c

CKM

BB

BB

?

0VVVVVV of Plot *tbtd

*cbcd

*ubud

Additional sources of CP violation needed

(solely responsible for CPV in SM)


Search for Super-PenguinsSearch for Super-Penguins Penguin amplitude in SM

Virtual, heavy particles can appear in loops

- can be relatively large, O(1)

- in general not CP-conserving

Double-CKM suppression:

Loop suppression:

Decay rates small BF<7·10-5

Super-penguin, beyond-SM?

0.04~VV~ tb*

ts2

0.02~mm

log12π 2

b

2ts

Example of SUSY diagram

SMrules


CPV Parameter sin2B0 K+K-K0 amplitudes:

CPAsymmetry:(B0/B0bar tags)

)cos( C)sin(sin2βNN

NN)(a

tagBtagB

tagBtagB

CP00

00

ΔmΔtΔmΔtΔt

~0

b

d

s

s

d

s

ss

d

s

b

d

0B 0B

0Bb

d

SKSK

• Interference term has different signs for B0/B0bar tags• Interference phase only due to B0/B0bar mixing (in SM)

2iβe

IF:KsJ/Ks-KK sin2βsin2β 0C Ks-KK

same asymmetry for J/KS and K+K-KS

super-penguins exist!

K+K-K0flavor

tag

e+

e-

0B0

B

0

0)KJ/,KKKBA(

)KJ/,KKKA(Barg

000

000

Ψ

ΨSM

superpenguins

or


Estimate of sin2in K+K-KS

Estimate of sin2in K+K-KS

From tree-dominated decaysB0->J/KS (SM reference point):

0.0260.675sin2β

(penguin-tree)

Experimental average of all penguins

0.050.52sin2β

b c

d

cWs

d

Tree

Penguin


Analysis of 3-Body DecayAnalysis of 3-Body Decay Selection of charm-less 3-body decays is tricky

- large background requires usage of several kinematic, event-shape variables in event selection- good particle ID

K+

K

B0KS L

L’=L L=even CP(K+K-KS)= +1

L=odd CP(K+K-KS) = -1

*[ CP(KKKS)= - CP(KKKL) ]

How to analyze angular momentum composition?

CP Violation measurement with additional complication- CP depends on angular momentum L between K+ and K-- (K+ K-)KS can be both CP-even and CP-odd *

-sin2

+sin2

-> (2fodd-1) sin2Dilution ifboth CP present!!


CP ContentCP ContentFractions of P-wave from analysis of angular moments:– 0.29 ± 0.03 over whole DP– 0.89 ± 0.01 in (1020) region

From 624±30K+K+K- decays

From 879±36 K+K-KS() decays

Need Dalitz plot analysis to measure CP

asymmetry

BABAR-CONF-06/40 (ICHEP06)

previously:- cut >1.1GeV (assume CP-even)- 1.0045<m<1.0345 (assume CP-odd)

Fraction of P-wave P-wavestrength


B0→K+K-K0 Isobar ModelB0→K+K-K0 Isobar Model

Charm(onium) contributions:D-K+, DS

-K+

c0K0

K0

f0(980)K0

X0(1550)K0

Non-resonant

toy Dalitz plot Component CP

K0 odd

f0(980)K0 even

X0(1550)K0 even

Nonresonant even(90%)odd(10%)

c0K0 even

Use flavor-symmetry to relateBABAR’s K+K+K- Dalitz plot


Dalitz Plot PDFDalitz Plot PDF Measure CP asymmetry in time-dependent Dalitz plot:

),()cos()sin(2222*

22

tddi

t

ttmAAtmeAAmAAe

Five observables: t, (t), m(K+K-), cosH, tag flavor

...cNRcXcfcc c0c0NRX0f0 00fA

...cNRcXcfcc c0c0NRX0f0 00fA

B0 amplitude

B0bar amplitude

CP Violation: Rate difference Phase difference

22

22

CP |c||c|

|c||c|A

)carg()arg(c

21

eff


… Add All K+K-K0 Final States

… Add All K+K-K0 Final States

(1020)

“X0(1550)”

c0

Non-resonant

f0(980)

K+K-KL

K+K-KS() K+K-KS()

Add K+K-KS(KS) and K+K-KL

All channels use same Dalitz plot model!~1500 signal events

138 ± 17

499 ± 52

879 ± 36


Average CP-AsymmetryAverage CP-Asymmetry

083.0354.0

089.010.0

eff

CPA

Combine KKKS+-, KKKS00, and KKKLAssume same CPV parameters for all KKK0

KKKS+- alone:

037.0079.0361.0

025.0079.0034.0

eff

CPA

Component Fraction (%)

K0 12.9±1.3

f0(980)K0 22.3±8.9

X0(1550)K0 4.1±1.8

Nonresonant 91±19

c0K0 2.8±0.8

D-K+, DS-K+ 4.9±1.1

SM:ACP=0=0.370


Measurement of Measurement of • Assume final state is mixture of CP-eigenstates (partial waves)

...NRccfcc NRc0c0f0 0fA

...NRccfcc NRc0c0f0 0fA

)2cos()()2sin()()( **2* ffff

iff AAmAAeeAAm

both real and imaginary b/c of CP-even, -odd interferences (->2)real in Q2B analyses (->sin2)

4.6

037.0079.0361.0 eff

eff

eff

eff


CPV in Low K+K- Mass CPV in Low K+K- Mass • Resonant fractions for m(K+K-)<1.1GeV

(1020)K0 57%

f0(980)K0 34%

Non-res 13%

• Low-K+K- mass fit for CPV parameters in K0 and f0K0 to reduce dependence on Dalitz plot model• K0 theoretically very clean (sin2)~ O(1%)• Fix S-wave, float isobar parameters for P-wave KKKs+- 252 ± 19

KKKs00 35 ± 9

KKKL 195 ± 33


CPV in Low K+K- Mass CPV in Low K+K- Mass Combined KKKS+-, KKKS00, and KKKL

05.016.006.0

10.020.018.0

eff

CPA

04.019.018.0

10.028.045.0

eff

CPA

• cross-check with Q2B analysis• syst. errors dominated by Dalitz plot model• consistent with SM, Belle

SM:ACP=0=0.370

KS

f0KS

• CPV measurements in f0Ks and Ks correlated (one background for the other)

asymmetry plot ±15MeV under


SummarySummary• Time-dependent Dalitz plot analysis opens new possibilities in study of penguin decays:

- measurement of asymmetry angle (instead of sine of the angle)- removes dilution for final states with opposite CP - model uncertainties included in fit

BABAR (sin2) Belle (sin2)

KKK0 0.661 ±0.12 ± 0.06

(all KKK0)

0.68 ±0.15 ±0.03 +0.21 −0.13

(excluding KS, KKKS only)

K0 0.12 ±0.31 ±0.10 0.50 ±0.21 ±0.06

f0(KK)K0 0.31± 0.32 ± 0.07 No result (f0K+K-)

• Lower sin2 than expected consistent with trend seen in other analyses• CPV results from penguin decays still intriguing, but need to work harder to observe new phenomena


More SlidesMore Slides


Angular MomentsAngular Moments

L

HLL cosP P

Piδ

S AeAA

- Decay rate in terms of moments of Legendre polynomials:

- Model-independent approach to extract CP content [BABAR, PRD71,091102]

- Assume S and P-waves decaying into K+K-

S-wave

P-wave

- Moments <PL> computed using sPlots[Pivk, Le Diberder, Nucl.Inst.Meth. A555]

- Fraction of P-wave:

0

2

P

P

45

Pf

K+

KKS

H

(angular momentum conservation)

K+K- CMS


BABAR/Belle 2006: B0 KKKS

Belle’s estimate (±10MeV): • K+K+K- Dalitz (140 fb-1) ~2.75±0.14%• ignores f0(980)

Belle’s helicity plot(±10MeV under mass)[Hazumi ICHEP06 talk]

BABARBABAR

B0K+K-K0 (347MBB)(bkg substracted)hep-ex/0607112

B+K+K+K- (230MBB) PRD72,032003(2006)

BelleBelle

non-zero yield below and above peak!

Estimates from BABAR results (±10MeV):• K+K+K- moments (347MBB): ~8±1%• K+K-K0 Dalitz (347MBB) and K+K+K- Dalitz (230MBB): f0K~10±3%, NR~3±1% -> 13±3%

Belle’s fitting range

Old BABAR fitting range


Dalitz Plot Isobar ModelDalitz Plot Isobar Model

LresLBres ZTFFf

Blatt-Weisskopf form factors Breit-Wigner Angular correlations

i

j

k

{ij}res

i

j

k

BF LF∑res

Resonant amplitude:

“Non-resonant”

)(mΓimmm1

2ijtotres

2ij

2res

)(pF mm

pp

Γ)(sΓ iLij

res

12L

i0

iresijtot

B

B

Single channel BW

Coupled channel BW (Flatté)

)gρg(ρimmm1

πππKKKres2ij

2res

2

φf

Decayamplitude

=

“resonant”

Documents

Sep 11, 2006SLUO Anual Meeting 20061 Search for Super-Penguins: CP Violation in B 0 ->K+K-K 0 D. Dujmic, SLAC For BABAR Collaboration D. Dujmic, SLAC For