Measurement of Z0-boson production at large rapidities in Pb–Pb collisions at √sNN = 5.02 TeV

Abstract

The production of bosons at large rapidities in Pb–Pb collisions at is reported. candidates are reconstructed in the dimuon decay channel (), based on muons selected with pseudo-rapidity and . The invariant yield and the nuclear modification factor, , are presented as a function of rapidity and collision centrality. The value of for the 0–20% central Pb–Pb collisions is , exhibiting a deviation of 2.6σ from unity. The results are well-described by calculations that include nuclear modifications of the parton distribution functions, while the predictions using vacuum PDFs deviate from data by 2.3σ in the 0–90% centrality class and by 3σ in the 0–20% central collisions.