Rare B decays with the CMS detector.

An angular analysis of the $\text{B}^{0}\!\to\!\text{K}^{\ast 0}\mu^{+}\mu^{-}$ decay is performed in $pp$ collisions at $\sqrt{s} = 7~\text{Te\hspace{-.08em}V}$, with a data sample corresponding to an integrated luminosity of $5.2~\text{fb}^{-1}$ collected by the CMS experiment at the LHC.The forward-backward asymmetry of the muons $A_{FB}$, the $\text{K}^{\ast 0}$ longitudinal polarization fraction $F_{L}$, and the differential branching fraction $\text{d}\mathcal{B}/\text{d}q^2$, are measured as function of the dimuon invariant mass squared, $q^{2}$.The results are in good agreement with the standard model expectations.