B->(D)tn in the MSSM Yasuhiro Okada (KEK) May 15, 2006 Flavour in the era of the LHC, 3rd meeting, CERN

B->tn, B->Dtn processes The Belle measurement of B to tn branching ratio. Inclusive B(b->ctn) was measured at LEP, but not exclusive B -> Dtn has not yet been found. 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.

Content of this talk Phenomenology of B->tn and B->Dtn processes. SUSY corrections to charged Higgs boson vertexes. Comparison with other processes. B->tn vs. B->Dtn, b->sg, Bs-> mm Charged Higgs production at LHC

Charged Higgs contributions to b-c and b-u transition tanb b c(u) t n W H- b c(u) t n tanb For B->tn For B->Dtn Essentially, both processes are sensitive to (tanb)2 /MH 2

B-> tn branching ratio in the type II 2HDM Theoretical uncertainty Charged Higgs effects

B->Dtn differential branching ratio f+, f- : Hadronic form factors, determined by B -> Dln process.

T.Miki, T.Mimura, M.Tanaka, hep-ph 0210052 Branching ratio normalized by B(B->Dln) Differential branching ratio Differential branching ratio is useful to identify new physics contributions

SUSY loop correction to the charged Higgs vertex. H.Itoh, S.Komine , and Y.Okada 2005 General type Yukawa couplings can be induced at SUSY one loop. Many interesting effects arise from the Higgs-exchange contributions in such processes as Bs->mm, b->sll, LFV t and m decays. SUSY loop effects do not decouple even if SUSY particles are very heavy as long as heavy Higgs bosons are relatively light. New contributions are important for large values of the ratio of two VEVs (tan b ) We have studied the effects in B ->Dtn and B->tn processes for MSSM with Minimal Flavor Violation (MFV). Inclusive b->ctn:J.A.Coarasa,R.A.Jimenez, and J.Sola 1997 Top vertex correction: M.Carena, D.Garcia, U.Nierste, C.E.M.Wagner, 2000 Effective coupling for the MFV: G.D.Ambrosio,G.F.Giudice,G.Isidori,and A.Strumia, 2002;A.Dedes and Pilaftsis, 2003;A.J.Buras,P.H.Chankowski,J.Rosiek, and L.Slawianowska,2003

Effective Yukawa coupling Tree Effective Yukawa coupling Loop induced Down-type quark coupling The correction factor

The correction can be large for tanb>30. Within the MFV scenario, there are no sizable contributions from up-type squark-chargino diagrams. Corrections to the H-b-c and H-b-u vertexes are the same. (The H-b-t vertex receives the stop loop correction.) The corresponding correction to the H-t-n vertex is not very large. Rd-1 Rt-1

B->tn and B->Dtn with SUSY loop corrections

Correlation between B->tn and B->Dtn Since the vertex corrections can be absorbed by the correlation of two branching ratios remains the same. Belle 06 Interesting to measure B->Dtn mode to resolve the twofold ambiguity.

Correlation to b->sg and Bs->mm The Higgs-exchange effects can affects other FCNC processes. Although the branching ratios of these processes depend on stop mixing, the constraint is strong (mild) for m<0 (>0). CDF 06

Comparison with charged Higgs boson production at LHC B->Dtn 5ab-1(90%CL) Belle B->tn excluded (95.5%CL) 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 K.A.Assamagan, Y.Coadou, A.Deandrea

Charged Higgs production at LHC Charged Higgs mass and coupling determination at ATLAS. K.A.Assamagan and Y.Coadou, Acta Phys.Pol. 2002 Determination of tanb in H+ -> tn mode

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 H-b-t (At=1TeV) H-b-c(u) (At=-1TeV) m>0 m<0 B->Dtn gb->tH+ ->ttn gb->tH+ ->ttb H.Itoh and Y.Okada Test of charged Higgs coupling universality => Squark flavor structure. The ratio gives R-1t.

Summary B->tn and B->Dtn processes are sensitive probe to charged Higgs boson interaction. These are especially important for large tanb case in the MSSM. Comparison with charged Higgs boson production at LHC is interesting, which provide the Universality Test of the charged Higgs couplings. In the SUSY case, we may be able to obtain some insight on flavor structure of the squark sector. For example, the top-Higgs coupling may be different from the charm (up)-Higgs coupling in the MFV scenario.