First measurement of Ω_c⁰ production in pp collisions at s=13 TeV

The inclusive production of the charm–strange baryon Ω_c⁰ is measured for the first time via its hadronic decay into Ω⁻π⁺ at midrapidity (|y|<0.5) in proton–proton (pp) collisions at the centre-of-mass energy s=13 TeV with the ALICE detector at the LHC. The transverse momentum (p_T) differential cross section multiplied by the branching ratio is presented in the interval 2<p_T<12GeV/c. The p_T dependence of the Ω_c⁰-baryon production relative to the prompt D⁰-meson and to the prompt Ξ_c⁰-baryon production is compared to various models that take different hadronisation mechanisms into consideration. In the measured p_T interval, the ratio of the p_T-integrated cross sections of Ω_c⁰ and prompt Λ_c⁺ baryons multiplied by the Ω⁻π⁺ branching ratio is found to be larger by a factor of about 20 with a significance of about 4σ when compared to e⁺e⁻ collisions.