Transcript Document 7304421

Flavor and Physics beyond
the Standard Model
Yasuhiro Okada (KEK)
June 21, 2007
“SUSY in 2010’s” Hokkaido Univ.
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Flavor physics in LHC era
LHC will start to explore TeV physics.
TeV = the scale of the electroweak symmetry
breaking.
New physics is most probably related to the
electroweak symmetry breaking physics. It could
involve new symmetries, new forces, or new
dimensions. Ex. SUSY, Little Higgs, extra-dim
models, etc.
 After 8 years of successful B factory experiments,
focus of flavor physics is also shifting to new physics
searches.

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Logical order
Gauge invariance
Higgs sector
Flavor sector
Unless we know what is the Higgs field, we do not know how to write the
Yukawa couplings.
Discoveries may not come in the logical order. “Mystery” ex. CPV in kaon.
Current mysteries.
Neutrino mass, Baryon number of the universe, Dark matter.
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Content of this talk



Status of quark flavor physics
New physics examples
SUSY, Extra dimensions
Neutrino and Lepton Flavor Violation
Super KEKB LoI hep-ex/0406071
SLAC Super B workshop proceedings: hep-ph/0503261
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Status of quark flavor physics

The Cabibbo-Kobayashi-Maskawa matrix works.
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Series of discoveries
2001
2001
2004
2006
2006
2006
2007
CPV in B->J/y Ks
b->sll
Direct CPV in B->Kp
b->dg
B->tn
Bs –Bs mixing at Tevatron
D-D mixing
All are consistent with the CKM prediction.
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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
+
Bs mixing and CP asymmetries
+
eK and B(K->pnn)
We know (or constrain) which sector is affected by new physics.
Improvement of f3/g is essential.
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Essential measurements for new physics
searches
|Vub| from e+e-B factories
f3/g from e+e- B factories and LHCb
The phase of the Bs-Bs amplitude from Bs->J/yf CP asymmetry at LHCb.
Improvements on rear decay observables:
CP asymmetry in B->f Ks, etc.
Direct and mixing-induced CP asymmetry in B->Xs g
Forward-backward asymmetry in b->sll
Roughly speaking, current data only constrain several 10’s%
new physics effects.
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SUSY and Flavor Physics



SUSY modes introduce SUSY
partners.
Squark/sleption mass matrixes are
new sources of flavor mixing and CP
violation.
Squark/slepton masses depend on
SUSY breaking terms as well as the
Yukawa coupling constants.
Quark mass
Squark mass
SUSY breaking
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Squark/slepton
mass matrixes carry information on the SUSY
breaking mechanism and interactions at the GUT scale.
Origin of SUSY breaking
(mSUGRA, AMSB, GMSB,
Flavor symmetry, etc.)
Renormalization
(SUSY GUT, neutrino Yukawa couplings etc.)
SUSY breaking terms at the Mw scale
(squark, slepton, chargino, neutralino, gluino masses)
Diagonal : LHC/LC
Off-diagonal: Future Flavor exp.
Top quark: Tevatron
KM phase: B factories
SUSY GUT example => T.Goto’s talk
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SUSY with a minimal flavor violation
(MFV)



Even in the case where the squark flavor mixing is
similar to the quark flavor mixing (MFV), a large
deviation from the SM is possible for a large value of
two vacuum expectation values (tan b )
Effects can be significant for the charged Higgs
boson exchange in B -> D tn and B -> tn.
Bs -> m m is enhanced by the loop-induced flavor
changing neutral Higgs coupling.
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Tauonic B decay
The Belle and Babar combined result of the B ->tn branching ratio.
This is sensitive to the charged Higgs boson exchange diagram
in 2 Higgs doublet model as well as SUSY models.
New contributions are important for the large tanb case
b
u
W
n
t
b
H-
u
n
t
Charged Higgs exchange contribution
depends on
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B(B->tn) vs. B(B->Dtn) ,B(b->ctn) ,B(B->D*tn)
There are four processes sensitive to charged Higgs exchanges.
Although inclusive b->ctn and B->D* tn are measured, B -> Dtn
process is the most useful to constrain the charged Higgs mass
combined with B->tn .
B(B->Dtn)/B(B->Dmn)
B(B->tn)
Belle+BABAR
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(LEP)
Belle 2007
B(b->ctn)/B(b->cen)
B(B->D*tn)
LEP
Belle
Y.Grossman, H.Haber and Y.Nir 1995
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Comparison with the charged Higgs boson production
at LHC
•The parameter region covered
by B decays and the charged Higgs
production overlaps.
•If both experiments find positive
effects, we can perform Universality
Test of the charged Higgs couplings.
Belle B->tn: excluded region
(95.5%CL)
B->tn: H-b-u coupling
B->Dtn : H-b-c coupling
gb->tH: H-b-t coupling
g
t
t
b
SUSY loop vertex correction
can break the universality.
H
K.A.Assamagan, Y.Coadou, A.Deandrea
K.A.Assamagan, Y.Coadou, A.Deandrea
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Even within the MFV frame, there can be sizable difference between the
corrections to the H-b-t vertex and the H-b-c(u) vertex.
Effective tanb= tanb x R-1t,c,u
B->tn
m<0
B->Dtn
gb->tH+ ->ttn, approximately
H-b-t
(At=1TeV)
H-b-c(u)
m>0
H-b-t
(At=-1TeV)
gb->tH+ ->ttb, approximately
H.Itoh and Y.Okada
The ratio gives
R-1t.
Test of charged Higgs coupling universality
=> Squark flavor structure.
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Bs->mm and SUSY
b
s
m
m
Loop-induced neutral Higgs exchange effects

SUSY loop corrections
can enhance B(Bs->mm)
by a few orders of
magnitude from the SM
prediction for large
values of tan b.
This is within the reach
of Tevatron exp.
A.Dedes, B.T.Huffman
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The discovery region
of a neutral Higgs boson
through pp->bf0->bmm
at LHC and the discovery
region of Bs->mm at
Tevatron and LHC overlap.
B(Bs->mm)=1x 10-8

5s discovery in
pp->bf0->bmm with 30 fb -1
att LHC
C.Kao and Y.Wang
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Large extra dim and B physics



Models with large extra dimensions
were proposed as an alternative
scenario for a solution to the hierarchy
problem.
Various types of models:
Flat extra dim vs. Curved extra dim
What particles can propagate in the bulk.
Geometrical construction of the fermion
mass hierarchy
=> non-universality of KK
graviton/gauge boson couplings
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KK graviton exchange
b->sll differential Br
AFB
T. Rizzo 1.5TeV
KK graviton exchange can induce
tree-level FCNC coupling.
Differential branching ratio of
b->sll processes.
P3
M=1TeV
P3 : 3rd Legendre polynomial moment
=> pick up (cosq )^3 terms due to
spin2 graviton exchange.
(In both flat and curved extra dim )
T.Rizzo
(Flat large extra dim case)
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KK gluon, KK Z-boson exchange in
warped extra dim.
In the warped extra dimension with
bulk fermion/gauge boson propagation
in order for the fermion mass hierarchy,
we put
Light fermion -> localized toward
Planck brane
Top and left-handed bottom ->
localized toward the TeV brane.
S(fKs) vs KK gluon mass
Generate tree level FCNC in KK
gluon and Z boson exchange.
1st KK gluon mass
G.Burdman
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Pattern of New Physics effects
SUSY
Large Extra
Dimension
model
Different pattern of the deviations from the SM prediction.
Correlation with other physics observables.
SLAC SuperB factory WS Proceedings
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Neutrino and LFV

Although the simple seesaw or Dirac neutrino
model predicts too small branching ratios for the
charged lepton LFV, other models of neutrino
mass generation can induce observable effects.
SUSY seesaw model (F.Borzumati and A.Masiero 1986)
Triplet Higgs model (E.J.Chun, K.Y.Lee,S.C.Park; N.Kakizaki,Y.Ogura, F.Shima, 2003)
Left-right symmetric model (V.Cirigliano, A.Kurylov, M.J.Ramsey-Musolf, P.Vogel, 2004)
R-parity violating SUSY model (A.de Gouvea,S.Lola,K.Tobe,2001)
Generalized Zee model (K.Hasagawa, C.S.Lim, K.Ogure, 2003)
Neutrino mass from the warped extra dimension (R.Kitano,2000)
Different pattern in the predictions on various mu and tau LFV processes.
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m and t LFV in SUSY models
In many models of SUSY, off-diagonal
terms of the slepton mass matrixes are induced
from Interaction at GUT /seesaw neutrino scales.
In many cases, LFV processes are dominated by the m->e g amplitude.
Explicit examples => T.Goto’s talk
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SUSY seesaw with a large tan b
R.Kitano,M.Koike,S.Komine, and Y.Okada, 2003
SUSY loop diagrams can generate
a LFV Higgs-boson coupling
for large tan b cases.
(t->3m K.Babu, C.Kolda,2002, t-> mh M.Sher,2002)
m
e
The heavy Higgs-boson exchange provides
a new contribution of a scalar type.
Higgs-exchange contribution
s
s
Photon-exchange contribution
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Numerical results : SUSY seesaw model
We calculated the mu-e conversion, mu > e gamma and, mu->3e
branching ratios in the SUSY seesaw model.
(Universal slepton masses at the GUT scale. Hierarchical neutrino masses.
A large tan b (tan b = 60). The Majorana neutrino mass = 10^14 GeV .)
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LFV in LR symmetric model
(Non-SUSY) left-right symmetric model
L<->R parity
Higgs fields, (bi-doublet, two triplets)
Low energy (TeV region ) seesaw mechanism for neutrino masses
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Four lepton interactions are dominant among various LFV processes.
In general,
Example of tau and mu LFV processes
A.Akeroyd, M.Aoki, Y.Okada,2006
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Summary

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In the LHC era, physics at the TeV scale will be
explored, which is connected to physics of
electroweak symmetry breaking. Role of the flavor
physics will be redefined in term of new findings.
Current data on the flavor physics are consistent
with the SM, but there are still a large room for new
physics effects.
In order to distinguish different models we need to
explore various flavor processes.
The Origin of small neutrino masses are still a
mystery. Pattern of charged lepton LFV processes
could provide an important clue on the model of the
neutrino mass generation.
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