Date of this Version
Eur. Phys. J. C (2019) 79:269
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)± → D0 +π± → K∓ +π± +π±. A cross section is measured in the fiducial region defined by the muon transverse momentum p_T^μ > 26 GeV, muon pseudorapidity |ημ| < 2.4, and charm quark transverse momentum p_T^c > 5GeV. The inclusive cross section for this kinematic range is σ(W + c) = 1026 ± 31 (stat)_−72^+76 (syst) 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.