First Measurement of the $D_s^{+}\to K^{\ast }(892{)}^0{\mu }^{+}{\nu }_{\mu }$ Decay, Study of Dynamics and Test of Lepton Universality with $D_s^{+}\to K^{\ast }(892{)}^0{\ell }^{+}{\nu }_{\ell }$ Decays

BESIII Collaboration, M. Ablikim, M. N. Achasov +715

We report the first measurement of the semileptonic decay $D_s^{+}\to K^{\ast }(892{)}^0{\mu }^{+}{\nu }_{\mu }$ and an improved measurement of the decay $D_s^{+}\to K^{\ast }(892{)}^0{e}^{+}{\nu }_e$ usin…