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

• Autor(a) principal: Sirunyan, A. M.
• Data de Publicação: 2021
• Outros Autores: Silveira, Gustavo Gil da, CMS Collaboration
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/236611
• topic: Aceleradores de partículas; Colisões proton-proton; Colisao de ions pesados; Hadron-Hadron scattering (experiments); Relativistic heavy ion physics

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 pT and of a geometric variable φ ∗ are measured, where φ ∗ highly correlates with pT 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.