Rare B Decays at CMS

The flavour changing neutral current decays can be interesting probes for searching for New Physics. Angular distributions of the decay $$\mathrm{B}$^0 \to $\mathrm{K}$^{*0} \mu^ +\mu^-$ are studied using a sample of proton-proton collisions at $\sqrt{s}=8\mathrm{T}\mathrm{e}\mathrm{V}$ collected with the CMS detector at the LHC, corresponding to an integrated luminosity of $20.5{\mathrm{f}\mathrm{b}}^{-1}$. An angular analysis is performed to determine $P_1$ and $P_5^{\mathrm{\prime }}$, where $P_5^{\mathrm{\prime }}$ is of particular interest due to recent measurements that indicate a potential discrepancy with the standard model. Based on a sample of 1397 signal events, $P_1$ and $P_5^{\mathrm{\prime }}$ angular parameters are determined as a function of the dimuon invariant mass squared. The measurements are in agreement with standard model predictions.