Measurement of the ? lepton polarization and R(D*) in the decay B�?D*???�? with one-prong hadronic ? decays at Belle

Abstract

With the full data sample of 772�106 BB? pairs recorded by the Belle detector at the KEKB electron-positron collider, the decay B??D??-??? is studied with the hadronic ? decays ?-??-?? and ?-??-??. The ? polarization P?(D?) in two-body hadronic ? decays is measured, as well as the ratio of the branching fractions R(D?)=B(B??D??-???)/B(B??D?-??), where - denotes an electron or a muon. Our results, P?(D?)=-0.38�0.51(stat)-0.16+0.21(syst) and R(D?)=0.270�0.035(stat)-0.025+0.028(syst), are consistent with the theoretical predictions of the standard model. The polarization values of P?(D?)>+0.5 are excluded at the 90% confidence level. � 2018 authors. Published by the American Physical Society.