Search for Nuclear Modifications of Meson Production in -Pb Collisions at

Abstract

Nuclear medium effects on 𝐵+ meson production are studied using the binary-collision scaled cross section ratio between events of different charged-particle multiplicities from proton-lead collisions. Data, collected by the CMS experiment in 2016 at a nucleon-nucleon center-of-mass energy of √𝑠NN=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→𝜇−⁢𝜇+ 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.