# Measurement of the shape of the $B_{s}^{0}\rightarrow D_{s}^{*+} \mu^{-} \nu_{\mu}$ differential distribution.

Cal`i S.

Comunicazione
I - Fisica nucleare e subnucleare
Aula Palazzo dell'Emiciclo - Sala Ipogea - Giovedì 26 h 09:00 - 12:30
We present the first comprehensive study of the $B_{s}^{0}\rightarrow D_{s}^{*+} \mu^{-} \nu_{\mu}$ decays, with $D_{s}^{*+}$ reconstructed in $D_{s}^{*+}\rightarrow D_{s}^{+} \gamma$. We used a sample of 1.6 fb${}^{-1}$ of data collected by the LHCb experiment at 13 TeV. The main result is the measurement of the differential decay spectrum as a function of the momentum transferred to the lepton pair, corrected for the efficiency and resolutions effects. We further extract the shape of the leading form factor for the $B_{s}\rightarrow D_{s}^{*} \mu \nu_{\mu}$ decay, using different parametrizations. This is a paramount measurement for the following studies of the Lepton Universality tests for the $B_{s}^{0}\rightarrow D_{s}^{*+} \tau^{-} \nu_{\tau}$ and $B_{s}^{0}\rightarrow D_{s}^{*+} \mu^{-} \nu_{\mu}$ decay rates comparison.