Andreas Crivellin Albert Einstein Center for Fundamental Physics
Andreas Crivellin Albert Einstein Center for Fundamental Physics ITP Bern Tauonic-B decays and 2 HDMs 14. 09. 2012 Indirect searches for New Physics
Outline: n Tauonic B decays B→τν n B→ D*τν n Two Higgs Doublet Models n n Type III n 2 HDM III and the MSSM n Conclusions 14. 09. 2012 Indirect searches for New Physics 2
Tauonic B decays n Tree-level decays in the SM via W-boson n Sensitive to a charged Higgs due to the heavy tau lepton in the final state. Observable SM Experiment Significance All three observables are above the SM prediction 14. 09. 2012 Indirect searches for New Physics 3
B→τν n Vub can be determined from n B→πlν n inclusive decay n Global fit to the CKM matrix Different determinations do not agree Vub problem 14. 09. 2012 Indirect searches for New Physics 4
( ) B→D * τν § Form factors uncertainties drop out to a large extend in the rations R(D) and R(D*). § R(D*) less sensitive to NP § CR cannot explain R(D) and R(D*) simultaneously but CL can. 14. 09. 2012 Indirect searches for New Physics 5
2 HDM of type II n One Higgs doublet couples only to down-quarks the other Higgs doublet only to up-quarks. n 2 additional free parameters: tan(β)=vu/vd and the heavy Higgs mass MH n Neutral Higgs-quark couplings are flavourconserving. n Chagred Higgs contribution to b→sγ requires m. H > 380 Ge. V T. Hermann, M. Misiak and M. Steinhauser 1208. 2788 14. 09. 2012 Indirect searches for New Physics 6
Tauonic B decays in the 2 HDM II n n n Contribution to B→τν necessarily destructive. needed for R(D*) too large. Cannot explain B→D(*)τν and B→Dτν simultaneously. ar. Xiv: 1205. 5442 Ba. Bar collaboration 1205. 5442 Disfavored by current data 14. 09. 2012 Indirect searches for New Physics 7
n Both Higgs doublets couple simultaneously to up and down quarks Flavour-changing neutral Higgs couplings n All flavour-changing elements and are constrained from FCNCs processes. Also constrained from charged Higgs diagrams, but is unconstrained. Contribution to tauonic B decays unconstrained from FCNCs 2 HDM III with MFV cannot explain B→τν, B→D(*)τν and B→Dτν n n n 2 HDM of type III 14. 09. 2012 Indirect searches for New Physics 8
2 HDM of type III with flavourviolation in the up-sector n n Constructive contribution to B→τν using is possible. B→D(*)τν and B→Dτν can be explained simultaneously using. Check model via Allowed regions from: A. C. , C. Greub, A. Kokulu 1208. 2788 14. 09. 2012 Indirect searches for New Physics 9
Effective Higgs-quark vertices in the MSSM new AC, ar. Xiv: 1012. 4840 14. 09. 2012 Indirect searches for New Physics 10
MSSM and the decoupling limit n Effective Higgs vertices generate important threshold corrections to the relation between Yukawa couplings Resummation of all (tan(β)) enhanced and quark masses. necessary. contribution L. Hall, R. Rattazzi, U. Sarid hep-ph/9306309, A. C. , L. Hofer, J. Rosiek, ar. Xiv: 1103. 4272 n MSSM corrections are too small to generate needed for B→τν and B→D(*)τν. NLO calculation in preparation including analytic results and tan(β) resummation in the generic MSSM. Indirect searches for New Physics 11 14. 09. 2012 n at order A. C. , Christoph Greub ar. Xiv: 1012. xxxx
Conclusions n First hints for violation of lepton universality tauonic B-decays. n 2 HDM II disfavored by current data. n 2 HDM of type III with flavour-violation in the up-sector can explain the B→τν, B→D*τν and B→Dτν. n 2 HDM III is the decoupling limit of the MSSM NLO matching is important. 14. 09. 2012 Indirect searches for New Physics 12
Effects of a right-handed Wcoupling on Vub inclusive CKM unitarity B→τν B→πlν 14. 09. 2012 Indirect searches for New Physics 13
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