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Patterns of flavor signals in supersymmetric models

Yasuhiro Okada (KEK/Sokendai)November 16, 2007University of Toyama

Work based on collaboration withToru Goto, Tetsuo Shindou, and Minoru Tanaka

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Flavor physics in the LHC era

The LHC experiment will start to look at the TeVscale physics directly next year.Past and ongoing experiments in flavor physics have already put strong constraints on new physics models. (KEK and SLAC B factories, Tevatron B physics, etc.)Several new experiments are under construction, LHCb(B), BESIII(τ,charm),MEG(µ->eγ), and future plans of Super B factory are considered.

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Plan of this talk

Present status of B physics and plan ofa future B factory.

Flavor signals in various SUSY models.

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Two B factroriesTwo B factory experiments, Belle at KEKB and BABAR at PEPII have been very successful.

total

KEKB

PEPII

Over 1ab-1 (=1000 fb-1) in total corresponding to 109 B-Bbar pairs.

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Status of quark flavor physicsThe Cabibbo-Kobayashi-Maskawa matrix works perfectly.

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Series of discoveries

2001 CPV in B->J/ψ Ks2001 b->sll2004 Direct CPV in B->Kπ2006 b->dγ2006 B->τν2006 Bs –Bs mixing at Tevatron2007 D-D mixing

All are consistent with the CKM prediction.

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Is this enough?Fit from tree level processesNot, to study New Physics effects.

In order to disentangle new physicseffects, we should first determine CKMparameters by “tree-level” processes.

|Vub|, φ3/γ

Bd mixing and CP asymmetries

εK and B(K−>πνν)

Bs mixing and CP asymmetries

+

+

+

We know (or constrain) which sector is affected by new physics.Improvement of φ3/γ is essential.

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Super B factoryPhysics case of future B factory experiments has been studied in many places.

Super KEKB LoI (hep-ex/0406071) SLAC Super B workshop (hep-ph/0503261) Super B CDR (arXiv:0709.0451) CERN workshop “Flavour in the era of the LHC”

At KEK, we started study on future upgrade of the current B factory experiment in 2001 by theorists, experimentalists and accelerator physicists. The effort is still continuing . Super KEKB aims to increase the luminosity by a factor of 50. The goal of a super B factory is to explore physics at the TeV scale from B, D, and τ decays.

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Physics sensitivity at a Super B factory.Super KEKB LoI(1) Unitarity triangle50 ab -1

5 ab -1

Consistency test at % level is possible at 50 ab -1.

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(2) CP asymmetry in penguin-dominated processes

Time-dependent CP asymmetry Current data(Dominant decay diagrams)B->J/ψKs

B->φKs

“tree”

“penguin”New phase (ex SUSY)

“sin 2φ1“ is the same in the SM

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(3) Rare B decaysThere are many rare decay processes sensitive to new physics effects.Electroweak penguin processes offer several theoretical clean

observables.

Inclusive and exclusive b->sγInclusive and exclusive b->dγInclusive and exclusive b->sll

1. Direct CP violation in b->sγ,dγ

2. Mixing-induced CP asymmetry in B->K*γ, Ksπ0γ.

(New phase)

(Right-handed photon operator)

3. Lepton forward-backward asymmetryin b ->sll.

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Super B sensitivity Super KEKB LoI50 ab -15 ab-1

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(4) Tau lepton flavor violation

The number of tau pairs produced at a B factory is similar to the number of BBbar pairs. Tau LFV processes can be searched for 10-9 -10-8

level.

Super KEKB LoI

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B physics in various SUSY modelsIn order to illustrate how B physics is useful to distinguish different SUSY models, we calculated various quark flavor observables in three representative SUSY models.

Models

1. Minimal supergravitymodel (mSUGRA)

2. SU(5) SUSY GUT with right-handed neutrino

3. MSSM with U(2) flavor symmetry

ObservablesBd-Bd mixing, Bs-Bs mixing.CP violation in K-K mixing (ε).Time-dependent CP violation in B ->J/ψKs, B->φKs, B->K*γ .Direct CP violation in b->s γ.

T.Goto, Y.O. Y.Shimizu, T.Shindou, and M.Tanaka, PRD(2002), (2004)

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A new study on quark and lepton flavor signals in SUSY models

T.Goto, Y.O.T.Shindou, and M.Tanaka, 2007

We have extended our previous work in the light of new developments and prospects of future experimental programs.

1. Bs physics

We take the Bs mixing as a new constraint

(CDF,2006)

2. Tau LFV

We have calculated τ -> µγ and τ -> eγ branching ratios in addition to µ->eγfor models with right-handed neutrinos.

3. Several technical improvements for calculations are incorporated.

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SUSY and Flavor PhysicsSUSY modes introduce SUSY partners.Squark/sleption mass matrixes are new sources of flavor mixing and CP violation.

SUSY breaking

W,Z,γ,H

gluon

lepton

quark

neutralino,

chargino

gluino )~(g

)~(χ

slepton

squark )~(q

)~(l

SM particles Super partners

Spin 1/2 Spin 0

Spin 1 Spin 1/2

Spin 1 Spin 1/2Spin 0

Quark mass

Squark mass

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SU(5) SUSY GUT with right-handed neutrinosIn the SUSY GUT case, the quark (neutrino) Yukawa coupling becomes a source of LFV (quark FCNC).

Quark Yukawa coupling Neutrino Yukawa coupling

GUT interactions

Quark flavor signalsTime-dep CP asymmetries in

B->φKsB -> K*γ

Bs->J/ψφ

Lepton flavor violation inµ->eγτ->µγτ->eγ

L.J.Hall,V.Kostelecky,S.Raby,1986;A.Masiero, F.Borzumati, 1986

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Neutrino Yukawa coupling and LFVLFV constraint depends on neutrino parameters

)2/sin(1 22 βννν vyM

ymR

T=Neutrino mass

LFV mass terms for slepton (and sdown).

Three cases are considered for MR.

2+ +⋅−≅ πδ νν 8/)/ln()||3()()( 20

2Rp

ijijL MMAyym

• Non-degenerate (I)• Degenerate case

(MR )ij= M δij

Severe µ−>eγ constraint

• Non-degenerate (II)

µ ->eγ suppressed(Casas and Ibarra, Ellis-Hisano-Raidal-Shimizu)

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MSSM with U(2) flavor symmetryA.Pomarol and D.Tommasini, 1996; R.Barbieri,G.Dvali, and L.Hall, 1996; R.Barbieri and L.Hall;R.Barbieri, L.Hall, S.Raby, and A.Romonino; R.Barbieri,L.Hall, and A.Romanino 1997;A.Masiero,M.Piai, and A.Romanino, and L.Silvestrini,2001; ….

The quark Yukawa couplings and the squark mass terms are governed by the same flavor symmetry. 1st and 2nd generation => U(2) doublet3rd generation => U(2) singlet

We do not consider LFV processes in this model

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Lepton flavor violation processes in SU(5) SUSY GUT with right-handed neutrinos

µ->eγ, τ->µγ,τ->eγ rates are calculated in three cases in the GUT model.

Degenerate Non-degenerate (I)

µ->eγτ->µγ τ−>eγ

Non-degenerate (II)

slepton mass 3TeV

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We take MR= 4x1014 GeV, which corresponds to 0(1) neutrino Yukawa coupling constants. Degenerate case:

B(µ->eγ) is the process that limits the SUSY parameter space, and can be close to the present bound even if the slepton mass is 3 TeV. Non-degenerate (I)

τ->µγ and µ->eγ can be close to the present boundsNon-degenerate (II)

τ->eγ and µ->eγ can be close to the present bounds.

µ->eγ vs. τLFV in non-degenerate (I)

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b-s and b-d transition processesWe have calculated the following observables for mSUGRA, three cases of SUSY GUT with RHN, and the U(2) model.

Direct and mixing-induced CP asymmetry of b->sγDirect and mixing-induced CP asymmetry of b->dγDifference of CP asymmetries for B->φKs and B->J/ψKsMixing-induced asymmetry of Bs->J/ψφ

Phase of the Bs mixing amplitude,~-0.04 in the SMPrecisely determined at the LHCb experiment.

We have taken account of constraints from LFV and EDM searches.

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Mixing-induced CP asymmetry: S(B->K*γ)U(2) modelSUSY GUT non-deg (I)mSUGRA

Deviation can be large in SUSY GUT non-deg(I) and U(2) caseExpected precision is 0.02-0.03 at Super B factory.

Super B

Estimation of experimental reach fromSuper KEKB LOI, SuperB:CDR, CERN WS on Flavour in the era of the LHC

sdown mass 3 TeV

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Mixing-induced CP asymmetry: S(B->ργ)

mSUGRA SUSY GUT non-deg (II) U(2) model

Super B

Expected precision is 0.08-0.12 at Super B factory.

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∆S(φKs)=S(B->φKs)-S(B->J/ψKs)

mSUGRA SUSY GUT non-deg (I) U(2) model

Super B

Expected precision is 0.02-0.03 at Super B factory.

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S(Bs->J/ψφ) for a new CP phase in the Bs mixing amplitude

SUSY GUT non-deg (I) U(2) modelmSUGRA

LHCb

Expected precision is 0.01 at LHCbfrom talk by T.Nakata at “SUSY 2010’s”, Hokkaido Univ. June 2007.

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mSGURA U(2) model

LHCb

SUSY GUT non-deg (II)

Correlation between ∆mBs/∆mBd and φ3(γ)

Precision of φ3 determination is 2-3deg at LHCb and 1-2 deg at Super B factoryThe error in the vertical axis is essentially the uncertainty of ξ. This is a sensitive test for new physics contributions to Bs and Bd mixing amplitudes unless they are cancelled as in the case of Minimal Flavor Violation.

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Pattern of new physics signalsPromising signals Possible deviations for some points

Pattern of deviations from the SM can provide a clue on physics determining the structure of the SUSY breaking sector.

• No sizable deviations from the SM are expected in mSUGRA.• LFV signals depend on the neutrino Yukawa texture and the assumption

of GUT for the seesaw-type neutrino generation.• Quark and lepton flavor signals are correlated in GUT.• Deviation in many processes are possible in the U(2) model.

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Conclusions

We have performed a comparative study on quark and lepton flavor signals for representative SUSY models; mSUGRA, MSSM with right-handed neutrinos, SU(5) SUSY GUT with right-handed neutrinos, and U(2) models.Each model predicts a different pattern of the deviations from the SM in b-s and b-d quark transition processes and muon and tau LFV processes. Bs physics at LHCb and tau LFV searches at a future B factory will be important parts of this program, along with the µ->eγ search at the MEG experiment.