1. Patterns of flavor signals in supersymmetric models
Yasuhiro Okada (KEK/Sokendai)
November 16, 2007
University of Toyama
Work based on collaboration with
Toru Goto, Tetsuo Shindou, and Minoru Tanaka

2. Flavor physics in the LHC era
The LHC experiment will start to look at the TeV scale 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(t,charm),MEG(m->eg), and future plans of Super B factory are considered.

3. Plan of this talk Present status of B physics and plan of
a future B factory.
Flavor signals in various SUSY models.

4. Two B factrories
Two B factory experiments, Belle at KEKB and BABAR at PEPII have been very successful.
total
KEKB
PEPII
Over 1ab-1 (=1000 fb-f) in total corresponding to 109 B-Bbar pairs.

5. Status of quark flavor physics
The Cabibbo-Kobayashi-Maskawa matrix works perfectly.

6. Series of discoveries 2001 CPV in B->J/y Ks 2001 b->sll
2004 Direct CPV in B->Kp
2006 b->dg
2006 B->tn
2006 Bs –Bs mixing at Tevatron
D-D mixing
All are consistent with the CKM prediction.

7. Is this enough?
Not, to study New Physics effects.
In order to disentangle new physics
effects, we should first determine CKM
parameters by “tree-level” processes.
Fit from tree level processes
|Vub|, f3/g
Bd mixing and CP asymmetries
eK and B(K->pnn)
Bs mixing and CP asymmetries +
We know (or constrain) which sector is affected by new physics.
Improvement of f3/g is essential.

8. Super B factory
Physics case of future B factory experiments has been studied in many places.
Super KEKB LoI (hep-ex/ )
SLAC Super B workshop (hep-ph/ )
Super B CDR (arXiv: )
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 t decays.

9. Physics sensitivity at a Super B factory.
(1) Unitarity triangle
50 ab -1
5 ab -1
Consistency test at % level is possible at 50 ab -1.

10. (2) CP asymmetry in penguin-dominated processes
Time-dependent CP asymmetry
Current data
(Dominant decay diagrams)
B->J/yKs
“tree”
B->fKs
“penguin”
New phase (ex SUSY)
“sin 2f1“ is the same in the SM

11. (3) Rare B decays
There are many rare decay processes sensitive to new physics effects.
Electroweak penguin processes offer several theoretical clean observables.
Inclusive and exclusive b->sg
Inclusive and exclusive b->dg
Inclusive and exclusive b->sll
1. Direct CP violation in b->sg,dg
(New phase)
2. Mixing-induced CP asymmetry in B->K*g, Ksp0g.
(Right-handed photon operator)
3. Lepton forward-backward asymmetry
in b ->sll.

12. Super B sensitivity
50 ab -1
5 ab-1

13. (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 level.

14. B physics in various SUSY models
T.Goto, Y.O. Y.Shimizu, T.Shindou, and M.Tanaka, PRD(2002), (2004)
In 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 supergravity model (mSUGRA)
2. SU(5) SUSY GUT with right-handed neutrino
MSSM with U(2) flavor symmetry
Observables
Bd-Bd mixing, Bs-Bs mixing.
CP violation in K-K mixing (e).
Time-dependent CP violation in B ->J/yKs, B->fKs, B->K*g .
Direct CP violation in b->s g.

15. 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, and calculate time-dependent
CP asymmetry in Bs-> J/y f mode, which is expected to be measured
up to the precision of 0.01 at LHCb.
(CDF,2006)
2. Tau LFV
We have calculated t -> mg and t -> eg branching ratios in addition to m->eg
for models with right-handed neutrinos.
3. Several technical improvements for calculations are incorporated.

16. SUSY and Flavor Physics
SUSY modes introduce SUSY partners.
Squark/sleption mass matrixes are new sources of flavor mixing and CP violation.
Super partners
SM particles
neutralino,
chargino
gluino
slepton
squark
W,Z,g, H
gluon
lepton
quark
Spin 1/2
Spin 0
Spin 1
Spin 1/2
Spin 1
Spin 1/2
Spin 0
Quark mass
Squark mass
SUSY breaking

17. SU(5) SUSY GUT with right-handed neutrinos
In 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 signals
Time-dep CP asymmetries in
B->fKs
B -> K*g
Bs->J/yf
Lepton flavor violation in
m->eg
t->mg
t->eg
L.J.Hall,V.Kostelecky,S.Raby,1986;A.Masiero, F.Borzumati, 1986

18. Neutrino Yukawa coupling and LFV
LFV constraint depends on neutrino parameters
Neutrino mass
LFV mass terms for slepton (and sdown).
Three cases are considered for MR.
Degenerate case
(MR )ij= M dij
Severe m->eg constraint
Non-degenerate (I)
Non-degenerate (II)
m ->eg suppressed
(Casas and Ibarra, Ellis-Hisano-Raidal-Shimizu)

19. MSSM with U(2) flavor symmetry
A.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) doublet
3rd generation => U(2) singlet
We do not consider LFV processes in this model

20. Lepton flavor violation processes in SU(5) SUSY GUT with right-handed neutrinos
m->eg, t->mg,t->eg rates are calculated in three cases in the GUT model.
Degenerate
Non-degenerate (I)
Non-degenerate (II)
t->eg
t->mg
m->eg
slepton mass
3TeV

21. t->mg and m->eg can be close to the present bounds
We take MR= 4x1014 GeV, which corresponds to 0(1) neutrino Yukawa coupling constants.
Degenerate case:
B(m->eg) 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)
t->mg and m->eg can be close to the present bounds
Non-degenerate (II)
t->eg and m->eg can be close to the present bounds.
m->eg vs. tLFV in non-degenerate (I)

22. b-s and b-d transition processes
We have calculated the following observables for mSUGRA, three cases of SUSY GUT with RHN, and the U(2) model.
S(K*g): Mixing-induced CP asymmetry of B->K*g
S(rg): Mixing-induced CP asymmetry of B->rg
A(sg): Direct CP asymmetry of b->sg
A(dg): Direct CP asymmetry of b->dg
DS(fKs)=S(fKs)-S(J/yKs):
Difference of mixing-induced asymmetries for B->fKs and B->J/yKs
S(Bs->J/yf): Mixing-induced asymmetry of Bs->J/yf
Chiral structure
New phase
Phase of the Bs mixing amplitude,
~-0.04 in the SM
New CP phase
We have taken account of constraints from LFV and EDM searches.

23. Mixing-induced CP asymmetry: S(B->K*g)
U(2) model
SUSY GUT non-deg (I)
mSUGRA
Super B
sdown mass
3 TeV
Deviation can be large in SUSY GUT non-deg(I) and U(2) case
Expected precision is at Super B factory.
Estimation of experimental reach from
Super KEKB LOI, SuperB:CDR, CERN WS on Flavour in the era of the LHC

24. Mixing-induced CP asymmetry: S(B->rg)
mSUGRA
SUSY GUT non-deg (II)
U(2) model
Super B
Expected precision is at Super B factory.

25. Direct CP Asymmety: A(b->sg)
mSUGRA
SUSY GUT non-deg (I)
U(2)
Super B
Some deviations from the SM in the U(2) case.
Precision will be at Super B factory.

26. DS(fKs)=S(B->fKs)-S(B->J/yKs)
mSUGRA
SUSY GUT non-deg (I)
U(2) model
Super B
Expected precision is at Super B factory.

27. S(Bs->J/yf) for a new CP phase in the Bs mixing amplitude
SUSY GUT non-deg (I)
U(2) model
mSUGRA
LHCb
Expected precision is 0.01 at LHCb
from talk by T.Nakata at “SUSY 2010’s”, Hokkaido Univ. June 2007.

28. Correlation between DmBs/DmBd and f3(g)
U(2) model
mSGURA
SUSY GUT non-deg (II)
LHCb
Precision of f3 determination is 2-3deg at LHCb and 1-2 deg at Super B factory
The error in the vertical axis is essentially the uncertainty of x.
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.

29. Pattern of new physics signals
Promising 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.

30. 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 m->eg search at the MEG experiment.