Z Boson Production in p+Pb Collisions measured by the ATLAS Experiment

The measurement of $Z$ bosons in heavy ion collisions is an excellent tool for probing the nucleus at the partonic level. The inclusive yield provides a stringent test of binary collision scaling. Recent ATLAS results demonstrate such scaling in Pb+Pb collisions. The 2013 p+Pb physics run at the LHC providing more than 30 nb$^{-1}$ of collisions at an energy of $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV has made a detailed study of $Z$ boson production in proton+nucleus interactions possible for the first time. These data may confirm binary scaling in the p-Pb system and help clarify the present ambiguity of centrality classifications in proton+nucleus collisions. Further, the momentum and rapidity differential yields of $Z$ bosons allow the detection of any modification of the initial state present in such collisions.