Open charm production cross section from combined LHC experiments in pp collisions at √(s) = 5.02 TeV

Open charm production in proton-proton collisions represents an important tool to investigate some of the most fundamental aspects of Quantum Chromodynamics, from the partonic mechanisms of heavy-quark production to the process of heavy-quark hadronisation. Over the last decade, the measurement of the production cross sections of charm mesons and baryons in proton-proton (pp) collisions was at the centre of a wide experimental effort at the Large Hadron Collider. Thanks to the complementarity of the different experiments, the production of charm hadrons was measured over a wide transverse momentum region and in different rapidity ranges. In this paper, the measurements of the charm hadrons D^0, D^*, D^+, D_s^+, Λ_c^+ and Ξ_c^0 performed by the ALICE, CMS and LHCb collaborations in pp collisions at the centre-of-mass energy √(s)= 5.02 TeV are combined to determine the total charm-quark production cross section σ_cc in a novel data-driven approach. The resulting total cc cross section is σ_cc (pp,5.02 TeV) = 8340.9 ± 217.8 (stat.) ^+367.1_-367.2 (syst.) ^+362.5_-457.5 (extr.) + 679.9 (Ω_c) μb. The measured charm-hadron distributions and corresponding cross sections are compared with the most recent theoretical calculations.