Search for nuclear modifications of B$^+$ meson production in pPb collisions at $\sqrt{s_\mathrm{NN}}$ = 8.16 TeV

Nuclear medium effects on B$^+$ meson production are studied using the binary-collision scaled cross section ratio between events of different multiplicities from proton-lead collisions. Data, collected by the CMS experiment in 2016 at a nucleon-nucleon center-of-mass energy of $\sqrt{s_\mathrm{NN}}$ = 8.16 TeV, corresponding to an integrated luminosity of 175 nb$^{-1}$, were used. The scaling factors in the ratio are determined using a novel approach based on the Z $\to$ $\mu^+\mu^-$ cross sections measured in the same events. The scaled ratio for B$^+$ is consistent with unity for all event multiplicities, putting stringent constraints on nuclear modification for heavy flavor.