New physics solutions for R D and R D∗

Abstract

Abstract Recent measurements of R D∗ have reduced tension with the Standard Model prediction. Taking all the present data into account, we obtain the values of the Wilson coefficients of each new physics four-fermion operator of a given Lorentz structure. We find that the combined data rule out most of the solutions based on scalar/pseudoscalar operators. By studying the inter-relations between different solutions, we find that there are only four allowed solutions, which are based on operators with (V − A), linear combination of (V − A) and (V + A), tensor and linear combination of scalar/pseudoscalar and tensor structure. We demonstrate that the need for new physics is driven by those measurement of R D and R D∗ where the τ lepton is not studied. Further, we show that new physics only in b→cμν¯ $$ b\to c\ \mu \overline{\nu} $$ is not compatible with the full set of observables in the decays B→Dlν¯ $$ B\to Dl\overline{\nu} $$ and B→D∗lν¯ $$ B\to {D}^{\ast }l\overline{\nu} $$.

Keywords

• Beyond Standard Model
• Heavy Quark Physics