Study of Drell-Yan dimuon production in proton-lead collisions at √s_NN = 8.16 TeV


Differential cross sections for the Drell-Yan process, including Z boson production, using the dimuon decay channel are measured in proton-lead (pPb) collisions at a nucleon-nucleon centre-of-mass energy of 8.16 TeV. A data sample recorded with the CMS detector at the LHC is used, corresponding to an integrated luminosity of 173 nb −1. The differential cross section as a function of the dimuon mass is measured in the range 15–600 GeV, for the first time in proton-nucleus collisions. It is also reported as a function of dimuon rapidity over the mass ranges 15–60 GeV and 60–120 GeV, and ratios for the p-going over the Pb-going beam directions are built. In both mass ranges, the differential cross sections as functions of the dimuon transverse momentum (p_{T}) and of a geometric variable ϕ * are measured, where ϕ * highly correlates with (p_{T}) but is determined with higher precision. In the Z mass region, the rapidity dependence of the data indicate a modification of the distribution of partons within a lead nucleus as compared to the proton case. The data are more precise than predictions based upon current models of parton distributions.

High Energy Physics - Experiment, Nuclear Experiment, Hadron-Hadron scattering (experiments), Relativistic heavy ion physics
Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Dragicevic, M., Erö, J., Escalante Del Valle, A., Frühwirth, R., Jeitler, M., Krammer, N., Lechner, L., Liko, D., Madlener, T., Mikulec, I., Pitters, F. M., Rad, N., Schieck, J., … Vetens, W. (2021). Study of Drell-Yan dimuon production in proton-lead collisions at $ \sqrt{s_{\mathrm{NN}}} $ = 8.16 TeV. In Journal of High Energy Physics (Vol. 2021, Issue 5). Springer Science and Business Media LLC.