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Flavor and Physics beyond the Standard Model. Yasuhiro Okada (KEK) June 21, 2007 “SUSY in 2010’s” Hokkaido Univ. . Flavor physics in LHC era. LHC will start to explore TeV physics. TeV = the scale of the electroweak symmetry breaking.
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Flavor and Physics beyond the Standard Model Yasuhiro Okada (KEK) June 21, 2007 “SUSY in 2010’s” Hokkaido Univ.
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.
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.
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
The Cabibbo-Kobayashi-Maskawa matrix works. Status of quark flavor physics
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.
|Vub|, f3/g Bd mixing and CP asymmetries + Bs mixing and CP asymmetries + + eK and B(K->pnn) 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.
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.
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
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) • 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 => T.Goto’s talk
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.
b n b n H- W t u u t 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 Charged Higgs exchange contribution depends on
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
(LEP) Belle 2007 B(b->ctn)/B(b->cen) B(B->D*tn) Belle LEP Y.Grossman, H.Haber and Y.Nir 1995
Belle B->tn: excluded region (95.5%CL) g t t K.A.Assamagan, Y.Coadou, A.Deandrea b H 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->tn: H-b-u coupling B->Dtn : H-b-c coupling gb->tH: H-b-t coupling SUSY loop vertex correction can break the universality. K.A.Assamagan, Y.Coadou, A.Deandrea
m<0 H-b-t (At=1TeV) H-b-c(u) H-b-t (At=-1TeV) m>0 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. B->tn Effective tanb= tanb x R-1t,c,u B->Dtn gb->tH+ ->ttn, approximately gb->tH+ ->ttb, approximately H.Itoh and Y.Okada Test of charged Higgs coupling universality => Squark flavor structure. The ratio gives R-1t.
b s m m Bs->mm and SUSY 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
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->bmmwith 30 fb -1 att LHC C.Kao and Y.Wang
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
KK graviton exchange b->sll differential Br T. Rizzo AFB 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)
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. • Generate tree level FCNC in KK gluon and Z boson exchange. S(fKs) vs KK gluon mass 1st KK gluon mass G.Burdman
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
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.
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
m e s s 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) The heavy Higgs-boson exchange provides a new contribution of a scalar type. Higgs-exchange contribution Photon-exchange contribution
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 .)
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
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
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.