cp violation measurements at b factories – present and future –

CP Violation Measurements at CP Violation Measurements at BB Factories – present and future – Factories – present and future –

Masashi Hazumi (KEK)

June 22, 2004SUSY04, Tsukuba, Japan

• Present– CKM angles

– New CP-violating phase

• Future: – Super e+e B factories

June 17-23, 2004 SUSY04, Tsukuba, Japan Masashi Hazumi (KEK) 3

Time-dependent Time-dependent CPCP violation violation“double-slit experiment” with particles and antiparticles“double-slit experiment” with particles and antiparticles

(Bigi-Carter-Sanda 1981) Large O(1) CP violation Very small hadronic uncertainty (~1% or less) !

b c

d

csd

J/KS

b

d cJ/KS

bcsddt

t

+

Quantum interference between two diagrams


Time-dependent Time-dependent CPCP violation violation“double-slit experiment” with particles and antiparticles“double-slit experiment” with particles and antiparticles

CP

(Bigi-Carter-Sanda 1981) Large O(1) CP violation Very small hadronic uncertainty (~1% or less) !


Measurement PrincipleMeasurement Principle

high-luminosity e+e collider with asymmetric beam energy (~108 B mesons) precise position measurement of B-meson decay vertices (z resolution~100m)

seemingly a crazy idea in 1980s 2 B factories (KEK, SLAC) in operation since 1999

e e+e: 8.0 GeV e+: 3.5 GeV

BCP

z

Btag

(4S) ~ 0.425

CP eigenstateCP eigenstate

z cB ~ 200 m

Flavor tagFlavor tag tz

c

10.58GeV/c2

(9.1/3.0 GeV at PEPII/BaBar)

O(1)ps


History ofHistory ofLuminosity FrontierLuminosity Frontier


11: Time-dependent : Time-dependent CPCP violation in violation in BB00 JJ// KKs etc.s etc.


sin2sin211 history history

sin21

7%precision


BB factories studying top quarks factories studying top quarks

Top-quark physics Direct production, Mass, width etc. CDF/D0Off-diagonal couplings, phase BaBar/Belle

tbtstd

cbcscd

ubusud

CKM

VVV

VVV

VVV

V


1()

(0,0)(0,1)

_ _(, )

3()

2()

B0 J/ KS(L), (2S) KS,

c1 KS, c KS

B0 +b ul with several approaches(excl. & incl.) _

BB mixing (md)

B D(*)l

B DCPK

B D(*)

B0

Unitarity Triangle determination at BaUnitarity Triangle determination at BaBar & BelleBar & Belle

B0

B D(Ks)


)]}Δcos()Δsin([1{4

);(0

0|

0 tmtmτ

etfB dd

B

/τt|

CP

B

ASP

)]}Δcos()Δsin([1{4

);(0

0|0

tmtmτ

etfB dd

B

/τt|

CP

B

ASP

C A is also used

(S, A) = (0.8, 0.0)

(S, A) = (0.8, 0.6)

Decay rate with direct Decay rate with direct CPCP violation violation

B0 + 　　 :direct CP violation may be large

)0;()0;(

)0;()0;(00

00

tBtB

tBtB

A

+


S

A

BB00 ++ : Significance of : Significance of CPCP violation violation 140fb1

Feldman-Cousins Analysis

(5.21) Observation of CP violation

hep-ex/0401029,

accepted by PRL

3.2 for A=0 and any S

2) Evidence for direct CP violation


Constraint on Constraint on 22 and and Belle140fb1

90 ≤ 2 ≤ 146 (95.5% CL)

2 (

deg.

) (deg.)

CL=0.683 (1)

CL=0.955 (2)

CL=0.9973 (3)

sin21 = 0.736

(deg.)

2 (deg.)

|P|/(|T|+|P|)

95.5% C.L. volume|P/T| = 0.45 (more stringent bound for |P/T|<0.45)


BB00

SlongClong

• Larger branching fraction than – (30 4 5) 106

• Small penguin pollution• 3 helicity states

– mixture of CP even and odd– Longitudinal fraction = 0.990.03

• Constraints on with isospin analysis– interference, non-resonant contributions, I=1

amplitudes neglected– Main systematics: CPV in B backgrounds

Preliminary

2 region for


33 withwith a new method a new method

b

u

u

s

c

u

Vub*

Vcs

B

b

u

u

s

c

u

Vcb*

Vus

B

D0

D 0

K

K

Ks

Ks

B+:

B-:

Dalitz analysis with BD0[Ks+-] K

interference

m+=m(Ks+), m=m(Ks) CPV: Asymmetry in Dalitz dist.:

r

r

A1

A2

|A2|

|A1|r =

Giri, Grossman, Soffer, Zupan, PRD68, 054018 (2003)


Dalitz analysis with Dalitz analysis with BB DD(( Ks Ks) K) K(*)(*)

73 events

M2(Ks) [GeV2 ]

M2 (

Ks

) [G

eV2 ]

B+

K*+

73 events

M2(Ks) [GeV2 ]

M2 (

Ks

) [

GeV

2 ]

B

K*

Fit to Dalitz distr. obtain , r

B DK

Most powerful method now !!

BB++ D D00KK++ && D* D*00KK++ combinedcombined

φ3=77 (stat) 13(syst) 11(model)

[26 <φ3 < 126 (95.5% CL)]

+1719

Preliminary

B DK


Constraints on Unitarity TriangleConstraints on Unitarity Triangle

2

_

3=95%CL3=95%CL


One phase to rule them all .. ?One phase to rule them all .. ?

• Beautiful agreements so far!– Triumph of Kobayashi-Maskawa model of CP violation

– More precise measurements needed for 2, 3• At least 1ab1 to do first precise measurements

• Difficulty in Baryogenesis• Many CP-violating phases in physics beyond the SM

b s (3rd 2nd )should be explored !

• Present constraints mainly with transitions between – 3rd 1st generations– 2nd 1st generations


Search for a new Search for a new CPCP-violating phase-violating phase


__Hint of new physics ?: CPV in Hint of new physics ?: CPV in bbssssss

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

Breakthrough to New Physics with loop (penguin) diagrams

Penguin diagram

virtual particle (top quark, and more ?)

Estimations on hadronic uncertaintiesGrossman, Isidori, Worah, PRD58, 057504 (1998)London, Soni, PLB407, 61 (1997) Grossman, Ligeti, Nir, Quinn, PRD68, 015004 (2003)Gronau, Grossman, Rosner, PLB579, 331 (2004) (not a complete list, sorry !)


More b More b s penguin anomalies s penguin anomalies

• Polarization in BVV decays

• Relations among BK branching fractions– Talk by A. Buras

• Large B ’Xs branching fraction

0

1O( )1

m2

≠0.43±0.10 (Belle, K*0)0.65±0.07 (BaBar, K*0)0.46±0.12 (BaBar, K*)0.95±0.11 (Belle, 0)0.96±0.16 (BaBar, 0K*)0.97±0.08 (BaBar, 0)


BB00 Ks, KKs, K++KKKs, Ks, ’Ks’Ks Fit sin21

B0 KS B0 KKKS B0 ’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 !


BB00 ’Ks, K’Ks, K++KKKs, fKs, fKs, Ks,

B0 K+KKs [hep-ex/0406005]

B0 f0(980)[]Ks

B0 ’Ks (81fb1)[PRL91, 161801 (2003)]

Sf0KsCf0Ks

+0.560.51

3rd error from quasi two-body approximation

SKKKsCKKKsCP-even fraction = 0.98 0.15 0.04

[hep-ex/0406040]

S’KsC’Ks

Preliminary

Preliminary


BB00 KKSS and and KKLL

SK0CK0

Signal yields are for all regions,histograms are for signal-enhanced regions.

+0.080.06

Preliminary


Vertexing for BVertexing for B00 Ks Ks00, Ks, Ks00

Reconstruct B Ks 0() vertex using Ks trajectory and boost trajectory

Ks

+

-

0B

0B

0

e+e-

boosted (4s)

z


B decay vertex with KsB decay vertex with Ks

B0 K*0( Ks0) [hep-ex/0405082]

SK*0CK*0

113fb1

B0 Ks0 [hep-ex/0403001]

SKsCKs

+0.380.47+0.270.38

events(68% w/ vtx)

Preliminary

Preliminary


b b s vs. b s vs. b c c

PDG2004

“SM” precision meas.

K0: Av = 0.14±0.33 (2.6 away from SM)

[Belle/Babar 2.3 away]

All b s (2.4 away from SM)


SSKsKs history history

?

New results coming soon !Stay tuned.

BaBar

Belle

Standard Model


Integrated luminosity nowIntegrated luminosity now

KEKB/Belle> 100 fb-1 this year (~6 months) !

PEPII/BaBar


Integrated luminosity in the near futureIntegrated luminosity in the near future

Oide’s scenario for KEKB Seeman’s scenario for PEPII• April 2004: 2.3A x 1.4 A y*=11 mm 1555

bunches L=8.4E33• July 2004: 2.5A x 1.6 A y*=10 mm 1600

bunches L=10E33• June 2005: 3.3A x 1.8 A y*=9 mm 1700

bunches L=15E33• July 2006: 3.9A x 2.0 A y*=8 mm 1715

bunches L=20E33• July 2007: 4.5A x 2.2 A y*=8 mm 1715

bunches L=24E33• With good integration reliability and trickle

injection:• 100 fb-1 more integrated by Summer 2004.• 500 fb-1 total integrated by Fall 2006.• About 1.0 to 1.3 ab-1 integrated by Fall 2009.


Super eSuper e++ee BB factories factories


Major upgrade plansMajor upgrade plans

SuperKEKB SuperBaBar

Peak lumi.

(cm-2s-1)

5 x 1035 1 x 1036

upgrade in ~2008 > 2010

Status LoI (Feb.04) ~530pages !!

LoI 1 year from now ?

KEK SLAC

http://belle.kek.jp/superb/loi/physics part to be submitted to hep-ex soon


Present situation: lucky for Super Present situation: lucky for Super BB factory ! factory !

• We know that– Standard Model (incl. Kobayashi-Maskawa mechanism) is the effective low ene

rgy description of Nature.

– However most likely New Physics lies in O(1) TeV region.• LHC will start within a few years and (hopefully) discover new elementary particles.

– Flavor-Changing-Neutral-Currents (FCNC) suppressed• New Physics w/o suppression mechanism excluded up to 103 TeV. New Physics

Flavor Problem

• Different mechanism different flavor structure in B decays (tau, charm as well)

Comprehensive studies of B decays with the luminosity upgrade will be quite effective and essential.


BB00 ( (cccc))KKs vs. s vs. KKss

2716 signals

6811 signals

1999-2003 data set (158fb-1) in 1 week

L=5 1035 cm2s1


One Snowmass year operation (5 abOne Snowmass year operation (5 ab-1-1))

J/Ks

KsS[Ks]input = +0.24

S Sf – SJ/Ks

[~ O(2) in SM]

SuperKEKB LoI


3-body 3-body CPCP eigenstateseigenstatesT. Gershon and M. Hazumi, hep-ph/0402097

X0

P0

0 Ks KL ’ f0 a0

0 000 00Ks 00KL 00 00’ 00 f0 00a0

Ks KsKs0 KsKsKs KsKsKL KsKs KsKs’ KsKsf0 KsKsa0

KL KLKL0 KLKLKs KLKLKL KLKL KLKL’ KLKLf0 KLKLa0

0 Ks KL ’ f0 a0

’ ’’0 ’’Ks ’’KL ’’ ’’ ’ ’’f0 ’’a0

f0 f0f00 f0f0Ks f0f0KL f0f0 f0f0’ f0f0f0 f0f0a0

a0 a0a0 a0a0Ks a0a0KL a0a0 a0a0’ a0a0 f0 a0a0a0

• Any final state with 3 spin-0 CP-eigenstate neutral particles is a CP eigenstate.• Many modes are available.• B0 KsKsKs most promising

– branching ratio already observed (Belle 78fb-1)– Pure b sss– Small background


BB KK : ultra-clean mode: ultra-clean modeM. Hazumi, PLB583, 285 (2004)

Belle 78 fb-1 (7 events)PRL91, 241802 (2003)

• Interference between B c( )K and 3-body b s process

• CP violation in the SM ~0, can be ~0.4 if new physics enters b s• Ultra-clean mode to reconstruct, almost no background

Sensitivity to new phase: K vs. Ks


Distinguish different new physics models !Distinguish different new physics models !

Different SUSY breaking scenarios can be distinguished !

T. Goto, Y.Okada, Y.Shimizu,T.Shindou, M.Tanaka, hep-ph/0306093+ SuperKEKB LoI


More tests of SUSY breaking scenariosMore tests of SUSY breaking scenariosSuperKEKB LoI

• S(Ks)• S(K*)• Br(b s)• A(b s)

• AFB(b sll)

• Br( )

50ab-1

“DNA identification”of new physics


CKM Unitarity Triangle (in)consistencyCKM Unitarity Triangle (in)consistency

5 ab1Two cases at


CKM Unitarity Triangle (in)consistencyCKM Unitarity Triangle (in)consistency

50 ab1Two cases at


•B → D

(BD)/(BD)at B factory with50 ab-1

““B-meson beam” with full reconstructionB-meson beam” with full reconstruction

Υ(4S)e- (8GeV) e+(3.5Gev)

B

B

Interesting decays•B → ul•B → •B → D•etc

full tagging

Unique at (4S)Need large statistics

0.2~1% for B+

(efficiency dependson purity).


Summary of physics reachSummary of physics reach


Summary of Summary of BB physics at present physics at present

• BaBar/PEPII and Belle/KEKB doing extremely good

• sin21 now measured with 7% accuracy

• CP violatioin in B0 observed

• First constraint on 3

• Tantalizing hint of new physics in b s CP asymmetries… and many more new observations for tomorrow ! (recall it is just a few years from the first obs. of B0 Ks

New ideas for measurements proposed constantly !


Summary for the future Summary for the future BB physics physics

• ~1ab-1 by ~2007: Exciting time will continue !– 2, 3 measurements first precise tests of the triangle

– Observation of direct CP violation (B0 , K+, etc.)

– (with luck) Observation of a new CP-violating phase

• Super B factory in the LHC era– play a key role to elucidate the new physics flavor problem.

– LHC results will serve as important inputs (similar to Tevatron)


SUSY2014 ?SUSY2014 ?

Yankee Stadium


Backup SlidesBackup Slides


Measurement PrincipleMeasurement Principle

~1 ps


CPCP violation in violation in BB00

A = +0.58 0.15(stat) 0.07(syst)S = 1.00 0.21(stat) 0.07(syst)

0.86 < LR 1.0

140fb1

hep-ex/0401029,

accepted by PRL


S

A

BB00 ++ : Significance of : Significance of CPCP violation violationBelle140fb1

Feldman-Cousins Analysis

(5.21) Observation of CP violation

3.2 for A=0 and any S

2) Evidence for direct CP violation

3.3 for “superweak” case


History of History of AA and and SS

Belle

BaBar

Difference at 2.2 level

BaBar/Belle average

A= 0.46 0.13


BB00 Ks, KKs, K++KKKs, Ks, ’Ks’Ks B0→KS

KK

B0→KKKS

(KK)

B0→’KS

Nsig(KS)=68(64%)

Nsig(KKKS)=

Nsig(’KS)=244(58%)

CP=even 103 16%

∫L dt = 140 fb-1

106 ev

361 ev

421 ev

199(55%)

[PRL 91, 261602 (2003)]


““B-meson beam” with full reconstructionB-meson beam” with full reconstruction

5 ab1 50 ab1

Observation of B+ D Observation of B+ K

12 5


Doable with mass spectrum ?Doable with mass spectrum ?

Very hard to distinguish different SUSY breaking scenarios from mass spectrum alone (at LHC)

quite similar


MissionMission

• Test of Kobayashi-Maskawa model of CP violation– Time-dependent CP violation

– Unitarity Triangle determination

– Direct CP violation

• Study rare B decays to find a hint of new physics– “Penguin” decays

• Many other topics– new resonances

– charm physics

– tau physics

cp violation measurements at b factories – present and future –

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