Tests of Light-Lepton Universality in Angular Asymmetries of B0 → D*- lv Decays

We present the first comprehensive tests of the universality of the light leptons in the angular distributions of semileptonic B-0-meson decays to charged spin-1 charmed mesons. We measure five angular-asymmetry observables as functions of the decay recoil that are sensitive to lepton-universalityviolating contributions. We use events where one neutral B is fully reconstructed in (sic)(4S) -> B (B) over bar decays in data corresponding to 189 fb(-1) integrated luminosity from electron-positron collisions collected with the Belle II detector. We find no significant deviation from the standard model expectations.

Automated summary

We have conducted the first comprehensive tests on the universality of the light leptons in the angular distributions of semileptonic B-0-meson decays. By measuring five angular-asymmetry observables, we found no significant deviation from the standard model expectations.