Weak decays of B meson and charmonium in the light of the search for new physics
Seminars
Seminar of Hadron Physics
Date and Time: Friday, 14 April 2017, at 11:00 AM
Venue: Blokhintsev Hall (4th floor), Bogoliubov Laboratory of Theoretical Physics
Seminar topic: «Weak decays of B meson and charmonium in the light of the search for new physics»
Speaker: Tran C. T. (MIPT and JINR)
Abstract:
Recent measurements of the semileptonic decays B0 → D(*)ℓνℓ provide some hints of lepton universality violation in the tau mode of these decays. An excess of 4σ over the standard model (SM) prediction has been observed by the BABAR, Belle, and LHCb collaborations. In this talk, I firstly provide a detailed description of the leptonic and semileptonic decays of the BB meson in the framework of the Covariant Confined Quark Model (CCQM) with particular emphasis on how to isolate heavy lepton mass effects in the semileptonic decays. Secondly, I consider possible new physics (NP) effects beyond the SM in the decays B0 → D(*)τντ. Starting with a model-independent effective Hamiltonian including non-SM four-fermion operators, I show how to obtain experimental constraints on different NP scenarios and investigate their effects on a large set of physical observables. The polarization of the tau as probe for NP in these decays is also discussed. Finally, I briefly discuss the semileptonic decays of J/ψ meson into D(s)(*) meson, where there have been some disagreements in the theoretical predictions between different approaches.