Additional information on heavy quark parameters from charged lepton forward-backward asymmetry

The determination of |v cb | using inclusive and exclusive (semi-)leptonic decays exhibits a long-standing tension of varying $$ mathcal{o}left(3sigma right) $$ significance. for the inclusive determination the decay rate is expanded in 1/m b using heavy quark expansion, and from moments of physical observables the higher order heavy quark parameters are extracted from experimental data in order to assess |v cb | from the normalisation. the drawbacks are high correlations both theoretically as well as experimentally among these observables. we will scrutinise the inclusive determination in order to add a new and less correlated observable. this observable is related to the decay angle of the charged lepton and can help to constrain the important heavy quark parameters in a new way. it validate the current seemingly stable extraction of |v cb | from inclusive decays or hints to possible issues, and even be sensitive to new physics operators.