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Recent results on CP violation from the B factory experiments. SLAC Summer Institute July 27, 2011. J. Chauveau LPNHE Université Pierre et Marie Curie, Paris-VI. On behalf of the BABAR Collaboration. Context. Motivation for the B factories The BABAR Physics Book SLAC-R-504 (1998)

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Recent results on CP violation from the B factory experiments


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recent results on cp violation from the b factory experiments

Recentresults on CP violation from the B factoryexperiments

SLAC Summer Institute

July 27, 2011

J. Chauveau

LPNHE

Université Pierre et Marie Curie, Paris-VI

On behalf of the BABAR Collaboration

context
Context

Motivation for the B factoriesThe BABAR Physics Book SLAC-R-504 (1998)

  • Primary goal:

To test the Cabibbo-Kobayashi-Maskawa model for CP Violation ( KvsB)

Overconstrain the Unitarity Triangle, the “UT” (sides, angles)

    • Does it close ?
    • Is there New Physics Beyond the Standard Model?

(CKM not enough for A(baryon))

  • Other goals

What now ?

J. Chauveau XXXIV SSI

outline
Outline
  • CP-violation (CPV) and the CKM model
  • The B factories
  • The angles of the UT (hadronic B decays)
    • b/f1
    • g/f3
  • The sides (semileptonic/leptonic) B decays
  • Rare hadronic/radiative B decays
  • Search for CPV in charm and tdecays
  • Outlook

B charmonium K0

B(D or D) K

B ffK

J. Chauveau XXXIV SSI

cp violation in b meson decay

CP

mixing

decay

CP violation in (B) meson decay

At least 2 amplitudes for CP violation to occur.

3 types of CP violation:

  • Direct charged and neutral B strong phases
  • In mixingneutral suppressed
  • In the interferenceneutral golden modes

betweenmixing and decay + others.

  • One or several types.

J. Chauveau XXXIV SSI

ckm the matrix and the triangle
CKM: the matrix and the triangle

W-

uj

Vij

/2

/3

/1

di

Wolfenstein parameterization

J. Chauveau XXXIV SSI

ckm matrix and the ut
CKM matrix and the UT

CKMfitter: http://ckmfitter.in2p3.fr , UTfit: http://www.utfit.org/UTfit/

J.Chauveau CPV in B and CKM

slide7

B factories

SLAC PEP-II

BELLE

KEK-B

1031 fb-1

770 M BB

531 fb-1

470 M BB

J. Chauveau XXXIV SSI

pep ii and babar

ON Υ(4S) peak

√s = 10.58 GeV

OFF peak

√s = 10.54 GeV

PEP-II and BABAR

Asymmetricenergies, Y(4S) boosted, bg=0.56

J. Chauveau XXXIV SSI

slide9

BABAR Collab. B. Aubert et al., Nucl.Instrum.Meth.A479:1-116,2002

J. Chauveau XXXIV SSI

the angles
The angles

/2

/3

/1

J. Chauveau XXXIV SSI

time dependent cp asymmetries the angle b f 1
Time dependent CP Asymmetries(the angle b/f1)

b

c

b

d(s)

J/ψ

KS(Ф)

c

d(s)

t

s

B(s)0

B(s)0

s

For B decaying to fCP (CP eigenstate) .

c

KS(Ф)

J/ψ

d(s)

d(s)

d(s)

c

t

b

V*td(s)

Im lf=hCP sin 2b

CP

mixing

decay

J. Chauveau XXXIV SSI

b charmonium k 0
B charmonium K0

770 M BB

H. Sahooat FPCP-2011

New Belle Result on full dataset

12681  114

10041  154

1981  46

943  33

# events

J. Chauveau XXXIV SSI

b c cbar s
b (c cbar) s

S=0.666 ± 0.031 ± 0.013

C=0.016 ± 0.023 ± 0.018

Phys.Rev.D79:072009,2009

S=0.668 ± 0.023 ± 0.013

C=0.007 ± 0.021 ± 0.014

PRELIMINARY (Moriond EW )

465 MBB

772 MBB

J/ KS

J/ KL

J. Chauveau XXXIV SSI

the angle b b ccs
The angle b (bccs)

In SM, expect, S=sin2b, C=0

sin2b= 0.678  0.020

b=(21.4  0.8) 0

J. Chauveau XXXIV SSI

the angle b b s penguin
The angle b (bs penguin)

loop

  • b  ssssameweak phase as b  ccs
  • onlyapproximate: depends on hadronic
  • parameters
    • oftenincreasingbeff
    • oftensmall.

J. Chauveau XXXIV SSI

the angle a f 2
The angle a/f2
  • Most sensitive results are not recent, not describedhere.

In a nutshell:

  • TDCP more complexbecause of the Penguin pollution.
  • Solvable in 2-body (pp) or quasi-2-body (rr)using isospin (Gronau-London [GL] method)
  • Dalitz analyses of the rpchannelsalso sensitive
  • The rrchannelusing GL is the most sensitive

(Penguin amplitude small and wellmeasurable)

d

π-

d

V*td

Vub

u

π+

u

b

d

u

b

u

B0

t

π+

B0

V*ub

π-

d

d

d

b

d

t

J. Chauveau XXXIV SSI

the angle g f 3
The angle g/f3
  • B D(*)K(*),D or D* D
    • sameD final state,henceb  uW and b cWinterfere (arg[Vub]=-g).
    • Pure Treeprocesses!
    • Large uncertaintiesbecause disparate magnitudes (color suppression)
    • Works for charged (and neutral) B’s.

s

b

u

K+

u

D0

c

Vub

b

c

B+

B+

D0

s

u

u

K+

u

u

J. Chauveau XXXIV SSI

f 3 g methods
f3/gmethods
  • Gronau London Wyler: D  CP eigenstates
    • R±CP= 1 + rB2 ±2rBcos(dB)cos(φ3),
    • A±CP= ±2rBsin(dB)sin(φ3) / R±CP

GiriGrossmanSofferZupan: Dalitz 3-body D decaysnew results

x+ = rB cos(dB+φ3 ) y+ = rB sin(dB+φ3 )

x− = rB cos(dB−φ3 ) y− = rB sin( dB−φ3)

Benefitsfromcharmmeasurements (CLEO-c)

  • Atwood DunietzSoni: DCSD(bc) + CA(bu) new results
    • RADS = rB2 + rD2 + 2 rBrD cos(dB +dD) cos(φ3),
    • AADS = 2 rBrD sin(dB +dD) sin(φ3) / RADS

rB, dB, dD, f3

J. Chauveau XXXIV SSI

the angle g f 3 ggsz
The angle g/f3 (GGSZ)
  • Assuming no CPV in D decays and neglecting D mixing,

s-

s+

  • Measure Dalitz plot from D*+Dp+ in the same data samplewith
  • Dalitz plot model to describe the dD(s+,s-) phase motion brings dominant systematics

s+

s-

PRL 105, 121801 (2010)

Phys. Rev. D 81, 112002 (2010)

HFAG-2010

J. Chauveau XXXIV SSI

new ggsz result
New GGSZ result

Giri, Grossman, Soffer, Zupan, PRD 68 05418 (2003)

A. Bondar, Y Poluetkov, PRD70, 072003 (2004)

J. Dalseno (Belle) EPS 2011

  • to remove model systematics, use optimal binning in the Dalitz plot (DP)
  • Uses the CLEO (eventually BES-III) quantum correlation in e+e-  DD at Psi ‘’

(s+)

(s-)

  • DP systematicsreduced by one half
  • losestatisticalprecision,
    • irrelevant for 10 ab-1samples

Preliminary

J. Chauveau XXXIV SSI

the angle g f 31
The angle g/f3

g = (71 +21 )0

-25

  • The only angle withexperimental
  • precisionworsethan the fit.
  • Great expectations from LHCb.
  • Recall, pure treeprocesses.

J. Chauveau XXXIV SSI

the sides

nt

l(t)

n

W-

b

q

l

u

Vub

W-

b

c or u

VcborVub

h/X

u,d

The sides

J. Chauveau XXXIV SSI

semi leptonic b decays
(Semi)leptonic B decays

R. Kowalewskiat Beauty 2011

  • |Vcb| (10-3)
    • Exclusive 38.9  1.1
    • Inclusive 41.9  0.7
    • Average 41.0  1.3

scale factor 2.2

    • in CKMfitter: 40.89 0.38 0.59
  • |Vub| (10-3)
    • Exclusive 3.25  0.12  0.28
    • Inclusive 4.25  0.15  0.20
    • Average 3.97  0.43

scale factor 2.0

    • In CKMfitter: 3.92  0.09  0.45
  • BR (B  tnt) (10-6)

In CKMfitter: 168  31

J. Chauveau XXXIV SSI

vub vub vcb status
Vub, Vub/Vcb, status
  • Marginal agreement betweeninclusive and exclusive measurementsboth for Vub and Vcb
  • VubfromtnexceedsVubfromsemileptonics

J. Chauveau -- Capri Workshop

global ckm fits

Whereis the new physics?

Global CKMfits

Roadmap

  • Pure treeprocesses to determine the SM parameters. g!
  • loops (mixing, FCNC (penguins)) to determinesameparameters and look if they are different.

CKMfitter: http://ckmfitter.in2p3.fr , UTfit: http://www.utfit.org/UTfit/

CKMfitter Input:

|Vud|, |Vus|, |Vcb|, |Vub|,

BR(B  tn)

Dmd, Dms, eK, sin2b, a, g.

CL=95,45%

SM p-value 3.3% (or 2.1s)

arXiv:1106.4041v1 [hep-ph]

  • acceptable consistency
  • there are tensions
  • Look for New Physics
  • in quantum fluctuation processes
  • akaloops

J. Chauveau XXXIV SSI

loops
Loops…
  • Charmlesshadronic B decays (gluonic Penguins)
    • 3-body e.g. B  PPP
    • quasi 2-body like B  VV, polarization puzzle
    • final states witheven more multiplicity

An exampleisBffK

  • Rare radiative decays (EW Penguins)

J. Chauveau XXXIV SSI

b f f k 1
B  f f K (1)
  • SM physics in the twodiagrams, canbeconsidered a single weak
  • amplitude, hence no CP-asymmetrypredicted by the SM.
  • A ‘New Physics’ diagrammay carry a non trivial phase, modelspredict
  • ACPas high as 40% [M. Hazumi PLB583, 285 (2004)]
  • This analysis:
  • measure the B+ and B0branching fractions below and under the hc
  • measure the corresponding CP-asymmetries
  • understand the partial wavesatplay

J. Chauveau XXXIV SSI

b f f k 2
B  f f K (2)

1

  • Signal: B to five kaons
  • backgrounds
    • peakingfrom B decays
    • continuum

Zones in (mf1, mf2) plane

4

3

2

5

multivariate techniques to fight the contimuum background. Here: a Fisher discriminant

Signal continuum

J. Chauveau XXXIV SSI

b f f k 3
B  f f K (3)

PRD84, 012001 (2011)

ACP(mff <2.85 GeV) = -0.10  0.08  0.02

ACP(mff in [2.94, 3.02] GeV) =

hc

cc

ACP ~0 consistent with SM

J. Chauveau XXXIV SSI

search for cpv in t charm
Search for CPV in t/charm
  • Charm
    • D mixingestablished
    • Is CPV next?
      • In mixing?
      • In decay?
    • Hugestatistics and favorable S/B in decays
      • 2-body
      • 3-body
      • Triple productasymmetries
      • Rare decays
  • Taus

Recentmeasurements by Belle and BABAR of

ACP in tKsp nt

Nothingsignificantyet

J. Chauveau XXXIV SSI

the bs
The Bs
  • Hadron collidersexperiments have the lead.
    • Bsmixing
    • Asl
    • BsJ/ 
    • bccs similar to Bd J/Ks, but B  VV
    • hence spin complexity.
    • BsJ/ f0 more tractable.
  • Belle (and BABAR) ranabove the Y(4S)
    • fs: Bs fraction in continuum (fromsemileptonicdecaysat BABAR),
    • BsJ/ f0 (seenat Belle)

J. Chauveau XXXIV SSI

summary and outlook
Summary and outlook
  • The wealth of the B factoryresultswerekey to establish the CKM model as the dominant mechanism of all observed CP-violation.
  • CP and CKM relatedresults are only one part of the B factoryharvest.
  • e+e- clean environmentenables to performquiteinvolved analyses.
  • There are stillmany analyses in progress
    • BABAR and BELLE collaborate to produce the PBF book to document ‘legacy’ analyses,
    • LTDA effort developped to keep BABAR dataset usable in the (far) future.
  • Nowis the time for bphysicsat hadron colliders.
  • What ‘New Physics’ at the energyfrontier (if any…), or above?
    • What impact on the flavorproblem?
    • Currentphenomenologyimplies a non generic NP flavorsector.
  • New e+e- colliders are approved to collectdatasets 50-100 bigger.

J. Chauveau XXXIV SSI

backup slides
Backup slides

J. Chauveau XXXIV SSI

babar topcite 100 references may 2010
BABAR TopCite100+ References (May 2010)
  • The BABAR Physics Book SLAC-R-504 (1998)
  • BABAR detector: Nucl.Instrum.Meth.A479:1-116,2002
  • HFAG: http://www.slac.stanford.edu/xorg/hfag/
  • CPV in B decay:
    • Discovery Phys.Rev.Lett.87:091801,2001 (BABAR), - 091802 - (Belle)
    • Long paper Phys.Rev.D66:032003,2002.
  • Charmless 2-body: Phys.Rev.Lett.89:281802,2002.
  • Ds0*(2317)+: Phys.Rev.Lett.90:242001,2003.
  • Polarization puzzle in B→VV: Phys.Rev.Lett.91:171802,2003.
  • B ---> X(s) l+ l- :Phys.Rev.Lett.93:081802,2004.
  • B ---> X(c) l nu and |V(cb)|: Phys.Rev.Lett.93:011803,2004.
  • B- ---> X(3872) K- : Phys.Rev.D71:071103,2005.
  • Direct CP in B0 ---> K+ pi-: Phys.Rev.Lett.93:131801,2004.
  • Ambiguity-free measurement of cos 2beta: Phys.Rev.D71:032005,2005.
  • X(4260): Phys.Rev.Lett.95:142001,2005.
  • t→e,m+g:Phys.Rev.Lett.96:041801,2006, Phys.Rev.Lett.95:041802,2005.
  • D mixing: Phys.Rev.Lett.98:211802,2007.

J. Chauveau XXXIV SSI

slide37

http://www-public.slac.stanford.edu/babar/Poster/slac_nobel_poster_2008.pdfhttp://www-public.slac.stanford.edu/babar/Poster/slac_nobel_poster_2008.pdf

J. Chauveau XXXIV SSI

amplitude structure in the sm
Amplitude structure in the SM

T

P

EWP

Cabibbo and color suppression

l4

l2

Accs ~ Vcb Vcs* Tccs + Vub Vus* Ps

Asss ~ Vcb Vcs* P + Vub Vus* P

Accd ~ Vtb Vtd* P + Vcb Vcd* Tccd

Auud ~ Vtb Vtd* P + Vub Vud* Tuud

(Tcus + Tucs) common D decay modes

Charmonium KS,L b

FKS b

D+D- b+f

p+p- aeff

GOLDEN

eff

l3

DK g

J.Chauveau CPV in B and CKM

b qq bar s penguin
b → qq-bar s (penguin)

s

  • Loop diagrams with same weak phase as ccbar s in SM
  • new physics in loops ?
  • New results available, in particular from amplitude analyses

J.Chauveau CPV in B and CKM

slide40

(flavor eigenstates) lifetime, mixing analyses

(CP eigenstates) CP analysis

Experimental Technique

Exclusive B Meson Reconstruction

B-Flavor Tagging

J. Chauveau XXXIV SSI

the angle gamma ads
The angle gamma (ADS)

Phys. Rev. D 84, 012002 (2011)

J. Chauveau XXXIV SSI

3 g results ggsz
3/gresults (GGSZ)

PRL 105, 121801 (2010)

D Ksp+p-

D Ks K+ K-

DK

D*K

D*D0p0

s-

D*K

D*D0g

DK*

mES

DE

s-

s+

mES

DE

s-

s+

J. Chauveau -- Capri Workshop

slide43

23

23

23

Phys. Rev. D 81, 112002 (2010)

GGSZ

PRL 105, 121801 (2010)

J. Chauveau -- Capri Workshop

summary on angles
Summary on angles
  • CP violation established
  • the angles alone bring a significant constraint on the UT apex
  • g/f3: more precision needed to bring a constraint

J. Chauveau XXXIV SSI

summary on sides

CP conserving

w/o tn

sl and tn separately

Vub averaged

Summary on sides

J. Chauveau -- Capri Workshop

methods

n

q

l

b

W-

c or u

VcborVub

h/X

u,d

nt

l(t)

b

W

u

Vub

R. Kowalewski Beauty 11

Methods
  • Semileptonic inclusive and exclusive B decays
    • Wellestablished analyses
    • Can use recoilsamples (hadronic or semileptonic tags)
    • Inclusive: bq ln + QCD corrections+OPE (as, L/mb)

also relevant for b s g

    • Exclusive: form factor(s) describing B  ln hadron – LQCD
    • Systematic trend where the inclusive results are higherthan exclusive ones.
  • Purelyleptonic B decays (B tn)
    • Theory more straightforward, still LQCD for fB
    • Underconstrainedevents  taggedsamples
    • Very hard measurements

J. Chauveau -- Capri Workshop

b k pp 0
B Kpp0

J. Chauveau XXXIV SSI

b k pp 01
B Kpp0

J. Chauveau XXXIV SSI

rare radiative decays
Rare radiative decays

J. Chauveau XXXIV SSI

t ks p nt
tKsp nt

J. Chauveau XXXIV SSI