Study of the expected sensitivity to the P$\mathrm{_5'}$ parameter in the $\mathrm{B^0 \to K^{*0}}\mu^+\mu^-$ decay at the HL-LHC

The expected sensitivity to the $\mathrm{P'_5}$ parameter in $\mathrm{B^0}\to {\rm K}^{*0}\mu^+\mu^-$ decays from an integrated luminosity of 300 and 3000 fb$^{-1}$ of pp collisions at a center-of-mass energy of 14 TeV at the HL-LHC is presented. Angular observables in the $\mathrm{B^0}\to {\rm K}^{*0}\mu^+\mu^-$ decay, such as the $\mathrm{P'_5}$ parameter, are of particular interest as their theoretical predictions are less affected by hadronic uncertainties. With an integrated luminosity of 3000 fb$^{-1}$, the uncertainties on the shape of the $\mathrm{P'_5}$ parameter will improve by up to a factor of 15, depending on the dimuon mass squared region, compared to the published results from 20 fb$^{-1}$ at 8 TeV.