b-hadron semileptonic decays with τ leptons in final states in LHCb

Lepton universality, described in the Standard Model, predicts equal coupling between gauge bosons and the three lepton families. SM extensions give additional interactions, implying in some cases a stronger coupling with the third generation of leptons. Semileptonic decays of b-hadrons provide a sensitive probe to such New Physics effects. The presence of additional charged Higgs bosons, required by such SM extensions, can have significant effect on the semileptonic decay rate of ¯B⁰ → D^∗+τ⁻¯ν_τ . The combination of experimental measurements give a deviation from the standard model prediction of about 4 σ. It is therefore important to perform additional measurements in this sector in order to improve the precision and confirm or disprove this deviation. Results obtained by LHCb on B⁰ → D^∗−τ⁺ν_τ decays, where the τ decays leptonically, are reported. The LHCb perspectives with other final states are discussed.