Measurement of associated production of a W boson and a charm quark in proton-proton collisions at $\sqrt{s} =$ 13 TeV

Abstract

Measurements are presented of associated production of a W boson and a charm quark (W + c) in proton-proton collisions at a center-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 35.7 fb(-1) collected by the CMS experiment at the CERN LHC. The W bosons are identified by their decay into a muon and a neutrino. The charm quarks are tagged via the full reconstruction of D* (2010)(+/-) mesons that decay via D*(2010)(+/-) D-0 + pi(+/-) -> K--/+ + pi(+/-) + pi(+/-). A cross section is measured in the fiducial region defined by the muon transverse momentum p(T)(mu) > 26 GeV, muon pseudorapidity vertical bar eta(mu)vertical bar < 2.4, and charm quark transverse momentum p(T)(c) > 5 GeV. The inclusive cross section for this kinematic range is sigma(W + c) = 1026 +/- 31(stat)(-72)(+76) pb. The cross section is also measured differentially as a function of the pseudorapidity of the muon from the W boson decay. These measurements are compared with theoretical predictions and are used to probe the strange quark content of the proton.Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia Maria de Maeztu: MDM-2015-0509Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia Maria de MaeztuFonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium)Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University (Thailand)Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand)Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium)Mobility Plus program of the Ministry of Science and Higher EducationConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Ministry of Education, Youth and Sports (MEYS) of the Czech Republic