Flavor and Physics beyond the Standard Model

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Flavor and Physics beyond the Standard Model

• Yasuhiro Okada (KEK)
• June 21, 2007
• SUSY in 2010s 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
Flavor sector
Gauge invariance
Higgs 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 CPV in B-gtJ/y Ks
• 2001 b-gtsll
• 2004 Direct CPV in B-gtKp
• 2006 b-gtdg
• 2006 B-gttn
• 2006 Bs Bs mixing at Tevatron
• D-D mixing
• All are consistent with the CKM prediction.

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Is this enough?
Fit from tree level processes
Not, to study New Physics effects. In order to
disentangle new physics effects, we should first
determine CKM parameters by tree-level
processes.
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 ee-B factories f3/g from ee- B
factories and LHCb The phase of the Bs-Bs
amplitude from Bs-gtJ/yf CP asymmetry at LHCb.
Improvements on rear decay observables CP
asymmetry in B-gtf Ks, etc. Direct and
mixing-induced CP asymmetry in B-gtXs g
Forward-backward asymmetry in b-gtsll Roughly
speaking, current data only constrain several
10s 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.

Diagonal LHC/LC Off-diagonal Future Flavor
exp.
Top quark Tevatron KM phase B factories
SUSY GUT example gt T.Gotos 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 -gt D tn and B -gt tn.
• Bs -gt 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 -gttn
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
Charged Higgs exchange contribution depends on
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B(B-gttn) vs. B(B-gtDtn) ,B(b-gtctn) ,B(B-gtDtn)
There are four processes sensitive to charged
Higgs exchanges. Although inclusive b-gtctn and
B-gtD tn are measured, B -gt Dtn process is the
most useful to constrain the charged Higgs
mass combined with B-gttn .
B(B-gtDtn)/B(B-gtDmn)
B(B-gttn)
BelleBABAR
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(LEP)
Belle 2007
B(b-gtctn)/B(b-gtcen)
B(B-gtDtn)
Belle
LEP
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.

B-gttn H-b-u coupling B-gtDtn H-b-c
coupling gb-gttH H-b-t coupling
SUSY loop vertex correction can break the
universality.
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-gttn
B-gtDtn
gb-gttH -gtttn, approximately
gb-gttH -gtttb, approximately
H.Itoh and Y.Okada
Test of charged Higgs coupling universality gt
Squark flavor structure.
The ratio gives R-1t.
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Bs-gtmm and SUSY
Loop-induced neutral Higgs exchange effects

• SUSY loop corrections can enhance B(Bs-gtmm) 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-gtbf0-gtbmm at LHC and the
discovery region of Bs-gtmm at Tevatron and LHC
overlap.
B(Bs-gtmm)1x 10-8 ? 5s discovery in pp-gtbf0-gtbmm
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
• gt non-universality of KK graviton/gauge
  boson couplings

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KK graviton exchange
b-gtsll differential Br
T. Rizzo
AFB
1.5TeV
KK graviton exchange can induce tree-level FCNC
coupling.
Differential branching ratio of b-gtsll processes.

M1TeV
P3
P3 3rd Legendre polynomial moment gt 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 -gt localized toward Planck brane
• Top and left-handed bottom -gt localized toward
  the TeV brane.
• Generate tree level FCNC in KK gluon and Z boson
  exchange.

S(fKs) vs KK gluon mass
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-gte g amplitude.
Explicit examples gt T.Gotos 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-gt3m K.Babu, C.Kolda,2002, t-gt mh M.Sher,2002)
The heavy Higgs-boson exchange provides a new
contribution of a scalar type.
Higgs-exchange contribution
Photon-exchange contribution
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Numerical results SUSY seesaw model
We calculated the mu-e conversion, mu gt e gamma
and, mu-gt3e 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
1014 GeV .)
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LFV in LR symmetric model
(Non-SUSY) left-right symmetric model
Llt-gtR 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

• 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.