Gautier Hamel de Monchenault

Moskow, 29 July 2006

Search for Physics Beyond the Standard Model

at B Factories

on behalf of the BABAR & BELLE CollaborationsCEA-Saclay DAPNIA/SPP

New Physics in Flavor SectorSummary of CKM constraints (pre-ICHEP06)

2006 CKM fit(relatively) good agreement

of experimental data with Standard Model predictions

unprecedented test of the flavor sector of the theory

Models of New Physics must satisfy SM-like flavor structure at low energy

no right-handed couplingssmall quark mixingonly one source of CP violation (CKM)

New sources of flavor or CP violationcan induce subtle deviations

from Standard Model predictions For instance, in MSSM• 124 independent parameters• 44 are CP violating

NP Strategy at B FactoriesM.Hazumi—plenaryR.Barlow—plenary

Improve CP asymmetry measurements in tree-dominated decays

Search for differences in CP asymmetriesbetween tree- and penguin- dominated processes

Look for deviations from Standard Model

Flavor Mixinglarge deviations in Bd system are unlikely

but SUSY can affect mixing in the Bs systemdistinguish measurements involving

flavor mixing or notFCNC in B-meson decayshelicity-conserving

examples of SUSY diagrams with intermediate squarks and gluinos

helicity-changing

FCNC in charm decays

Very rare B decays (e.g. leptonic)

Lepton Flavor Violating processes(not covered in this talk)

Theoretical Tool: the Operator Product

Example:CKM

b → sγdecay

amplitude

Wilson coefficientshort-distance physics,

perturbative at mW, RGE: mW → mB

local operatoreffective Lagrangian

Heavy Quark Expansionin power of Λ/mB

New Physicscan affect specific Wilson coefficients

contributionof New Physicscan lead to introducing non-SM operators

(e.g. right-handed currents)

b → sGluonic

Penguins

Measurements of sin2βwith s-Penguin Modes

( )0,0 ( )0,1

( )η,ρ

Re

Im

α

βγ

uR tR

UT

s-Penguins: Compilation of Results

New physicsmay affect

different modesin different ways:

→ use the pattern ofdeviations to go beyond

the naïve average

mixing-induced

direct

time-dependent CP asymmetry

M.Hazumi—plenaryA.Lazzaro—CPVK.Hara—CPV

ICHEP06

pre-ICHEP06: Naïve average of

“s-Penguin” S coefficients2.4σ away from reference

value of sin2β (cc)

Deviations from Standard Model

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Erro

r on

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e am

plitu

de

K*γf0KSKSπ0

φ KSη’KSKKKS

Projected errors as a function of time Significance of deviationfrom Standard Model expectation

as a function of luminosity (assuming fluctuations aroundpre-ICHEP06 central values)

BABAR+Bellein 2008

Num

ber

of

stan

dard

dev

iatio

ns

integrated luminosity (/fb)

φ KS

η’KS

average

Theoryerrors

Full analysis: for each model

constraints in the plane of the two NP parameters (modulus and phase)

Discriminating Among NP ModelsExploit the pattern of deviations ∆S in the various modes to discriminate among different models

Wilson coefficients:

Three NP models, six scenarios:• NP only in the Z0-penguin coupling

• NP in Kaluza-Klein gluon excitations

• NP in chromo-magnetic operator

SM

Six N

P scenarios

S Exclusion vslum

inosity

Buchalla, Hiller, Nir, Raz(hep-ph/0503151)

Flavor Mixing

Test Standard Model in Bd Mixing

SM

Basic assumptions:no new Physics at tree-level3-generation unitarity

determine the apex of UTfrom Vub and γ

Mixing amplitude

Observables:

contributionof NP

SM favored(but NP

not excluded)

various analyses … similar conclusions

K. Agashe et al, hep-ph/0509117 (2005)FJ.Botella et al, hep-ph/0502133 (2005)

UTfit, hep-ph/0509219 (2005)J.Charles (CkmFitter) hep-ph/0606046 (2006) Suggests mixing unaffected by NP

one source of flavor & CP violationin Yukawa couplings (MFV)

b → sElectroweak

Penguins

Sensitive Probes of New Physics

Z/photon penguin (C7 & C9) W-box (C10)Radiative penguin (C7 )

Examples of b → s, EW-penguins:

SM: top quark dominates in loops → reliable calculations

Many observables:rates (inclusive & exclusive)direct CP asymmetries, ACP (inclusive & exclusive)time-dependent CP asymmetries, S & C forward/backward asymmetries, AFBpolarizations (photon, K*…)mass and angular distributions of lepton pairetc.

with different sensitivity to New Physics

Radiative Decays: b → s γM.Convery—HQA.Limosani—HQ

photon energy

BABAR (88.9M BB) PRD72, 052004 (2005)

Semi-inclusive analysis:sum of 38 exclusive modes

(~44% of total)γsb →The FCNC transition

has been heavily studied by CLEO

then by BABAR and Bellein a variety of ways• exclusive (B → K*γ)• semi-inclusive• fully inclusive

b → s γ : Fully Inclusive Analysis

BELLE (152M BB) PRL93, 061803 (2004)

effic

ienc

y co

rrec

ted

Huge background subtractionsystematic error dominated

by off-resonance statistics BABAR (88.5M BB), hep-ex/0507001

b → s γ : Compilation of Results

SM Predictions~3.6 ± 0.4 x 10-4

NP B631, 219 (2002)NP B704, 56 (2005)EPJ C40, 165 (2005)

A triumph for the Standard Model!

Improvements (circa 2008)theory: NNLO → 5%experiment: statistics x 4 and

lower energy cut

Bounds on |C7| (sign not constrained)

So far all measurements areconsistent with SM predictions

(typical errors: <10%)

SUSY: probe “LR” mass insertions

Direct CP asymmetryhep-ex/0603003

consistent with SM (~0)

and−+→ llsB −+∗→ ll)(KBD.Kovalskyi—CPV

Exclusive branching fractionsalready measured with errors comparableto theory uncertainties

Inclusive branching fractions

SM

C7 → – C7CP asymmetriesconsistent with zero with large errors

Ratio muon to electron modesensitive to SUSY Higgs at large tanβso far consistent with SM (=1)

inclusive

BELLE, PR D72, 092005 (2005)

q2/mB2

K* polarizationconsistent with SM

SMC7 → – C7

BABAR, PRL 93, 081802 (2004)

wrong-sign C7 disfavored

Forward-Backward Asymmetry−+∗→ ll)(KB

Vector (C7,C9) and Axial-vector (C10) interference

Result K*ll:both experiments favor

positive integrated asymmetry

SUSY: probe “RR” and “LL” mass insertions

SM

fit for leading termof effectiveWilsoncoefficient

Crosscheck on Kll:AFB consistent with SM (zero)

SM

C9 C10→ – C9C10

Observation of b → d γ

BABAR

BELLECDF

W.A.:

Smaller SM amplitudehigher NP sensitivity

no hint of New Physics yet…

8.2 evts

20.8 evts

5.9 evts

BABAR (347M BB) CONF-06/034

BELLE (386M BB)hep-ex/0506079

42 evts

39 evts

11 evts

likel

ihoo

d “p

roje

ctio

ns”

(NEW)

D.Kovalskyi—CPV

Right-Handed Currents in B → K*γ ?

γπ )K(B 00S

0 →In the SM the photon is predominantlypolarized (left-handed in b → s γ)

16157N *K ±=γ

Therefore the final state is almost flavor specific and the TD asymmetryis suppressed

(SM: ~ − 0.1)

large values of S probe non-standard polarization of the photon

If non-SM “non-dipole” contributions to the amplitude contributelarger values of S are possible

BABAR (232M) + Belle (275M)in K*(892) region (0.8-1.0 GeV)

So far no evidence for deviation from SM expectation(much higher statistics is required)

Leptonic Decays

Select one & three

prongs

plot extra energyin calorimeter

(GeV)

B → τν : Purely Leptonic Decay

Recoil technique (semileptonic and hadronic)

semileptonic tags

BABAR (320M BB) CONF-06/028 BELLE (447M BB) CONF-0671

hadronic tagsW-annihilation

T.Browder—CPVS.Sekula—CPV

combining 5 tau-decay modescombining 4 tau-decay modes

(3.5 standard deviations)

B → τν : Constraints on 2HD-Models

Charged Higgscontribution

to the decay

In 2-Higgs doublet models coupled separatelyto up- and down quarks (incl. MSSM):

(always destructive interference)

(no helicitysuppression)

Example of limits in tanβ-m(H±) plane

using Belle’s result and• fB from unquenched lattice• Vub from HFAG

for b → sγ : also charginos & squarks contribute→ various MSSM scenarios

More Leptonic DecaysS.Sekula—CPV

hadronic tags

BABAR (230M BB) CONF-06/001

no signal

no event 3 eventsLimits at 90% C.L.

BABAR (300M BB) CONF-06/026

SM:

SM: No hint of New Physics in leptonic decays…

FCNC inCharm Decays

&)K,h(hD )s( π=→ −+++ ll −++ → llpcΛ

−+→ lluc XX SM: strong GIM suppression

but Long-Distance contributions→ veto resonances (e.g. φ)

SM (short-distance)

SMSM+SUSY

BABAR (288 fb-1)• place limits in the range

4-40 .10-6 (at 90%)• goal: reach the 10-6 range

and start to constrain SUSY

BF ~ O(10-8)

PR D66, 140409 (2002)

BABAR (288/fb) hep-ex/0607051

Conclusions

Recent triumphs of the Standard Model Standard Modelin a

very good shape

“tension” between sin2β and |Vub|

Points of slight disagreement to keep an eye on

∆sin2β<0 (2.5-sigma) for s-penguin modes

New Physicsin BB mixing?

Kπ puzzle: ~2-sigma effect in B → KπNew Physics

in b → s-gluon?

B factories to double their statistics in the next two years

b → s γ , b → s l+ l− , b → d γ , B → τ ν , etc.Overall consistency of the CKM fit

Complementarity of B-factory & flavor physics experimentswith experiments at the energy frontier (Tevatron, LHC)

Two main classes of New Physics models are favored by the data

Minimal Flavor Violation (MFV) Results inflavor physics

are crucialfor NP model

building

models with no new source of flavor & CP violationBeyond MFV

new sources of CPV confined in b → s transitions

Gautier Hamel de Monchenault

ICHEP06, Moskow, 29 July 2006

on behalf of the BABAR & Belle CollaborationsCEA-Saclay DAPNIA/SPP

Physics Beyond the Standard Modelat B Factories