Angular analysis of the decay ${\mathrm B^{+} \to \mathrm K^{*+} \mu^{+} \mu^{-}}$ in proton-proton collisions at $\sqrt{s}=8~\mathrm{TeV}$

Angular distributions of the decay ${\mathrm B^{+} \to \mathrm K^{*+} \mu^{+} \mu^{-}}$ are studied using events collected with the CMS detector from $\sqrt{s}=8~\mathrm{TeV}$ proton-proton collisions, corresponding to an integrated luminosity of $20.0~\mathrm{fb}^{-1}$. The forward-backward asymmetry of the muons and the longitudinal polarization of the $\mathrm K^{*+}$ meson are determined for an integrated sample and as a function of the dimuon invariant mass squared. These are the first results from this exclusive decay mode and are in agreement with standard model predictions.