LHCb Collab.
The fraction of Z+jet events that contain a charm jet is measured for the first time in the forward region of proton-proton collisions. The data sample used corresponds to an integrated luminosity of 6 fb−1 collected at a center-of-mass energy of 13 TeV with the LHCb detector. The ratio of production cross sections σ(Zc)/σ(Zj) is determined in intervals of Z-boson rapidity in the range 2.0 < y(Z) < 4.5. A sizable enhancement is observed in the forward-most y(Z) interval, which could be indicative of a valence-like intrinsic-charm component in the proton wave function.
Study of Z bosons produced in association with charm in the forward region