Open charm production and asymmetry in pNe collisions at $\sqrt{s_{NN}}$ = 68.5 GeV

A measurement of D${}^0$ meson production by the LHCb experiment in its fixed-target configuration is presented. The production of D${}^0$ mesons is studied with a beam of 2.5 TeV protons colliding on a gaseous neon target at rest, corresponding to a nucleon-nucleon centre-of-mass energy of $\sqrt{s_{NN}}$ = 68.5 GeV. The sum of the D${}^0$ and ${\overline{D}}^0$ production cross-section in pNe collisions in the centre-of-mass rapidity range y${}^{\star }$$\in$ [-2.29, 0] is found to be σ${}_{D^0}^{y^{\star }\in [-2.29,0]}$ = 48.2 ± 0.3 ± 4.5 μb/nucleon where the first uncertainty is statistical and the second is systematic. The D${}^0$ - ${\overline{D}}^0$ production asymmetry is also evaluated and suggests a trend towards negative values at large negative y${}^{\star }$. 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.