Open charm production and asymmetry in pNe collisions at √s_NN = 68.5 Ge\hspace{-1.00006pt}V

A measurement of D⁰ meson production by the LHCb experiment in its fixed-target configuration is presented. The production of D⁰ mesons is studied with a beam of 2.5 Te\hspace{-1.00006pt}V protons colliding on a gaseous neon target at rest, corresponding to a nucleon–nucleon centre-of-mass energy of √s_NN = 68.5Ge\hspace{-1.00006pt}V. The sum of the D⁰ and D̅⁰ production cross-section in pNe collisions in the centre-of-mass rapidity range y^⋆ ∈ [−2.29,0] is found to be σ^{y⋆∈[−2.29,0]}_D0 =48.2±0.3±4.5μb/nucleon where the first uncertainty is statistical and the second is systematic. The D⁰ − D̅⁰ production asymmetry is also evaluated and suggests a trend towards negative values at large negative y^⋆. The considered models do not account precisely for all the features observed in the LHCb data, but theoretical predictions including 1% intrinsic charm and 10% recombination contributions better describe the data than the other models considered.