Production mechanisms of open-heavy flavor mesons

In this paper we discuss different mechanisms of open-heavy flavor meson production. Using the color dipole framework, we analyze in detail the contributions of the conventional two-Pomeron fusion and the three-Pomeron fusion correction. In a parameter-free way we found that the three-Pomeron mechanism is significant for 𝐷-meson production in the small-𝑝𝑇 kinematics, although it is less important at large 𝑝𝑇, as well as for 𝐵-mesons. The inclusion of the three-Pomeron mechanism significantly improves the agreement of theoretical predictions with experimental data in the small-𝑝𝑇 kinematics. We also consider the nonprompt charmonia production, and demonstrate that the theoretical results are in reasonable agreement with experimental data. Finally, we compare the theoretical predictions for the dependence on multiplicity of coproduced hadrons to experimental data recently measured by the ALICE collaboration. We found that, contrary to naive expectations, the contribution of the three-Pomeron mechanism has only a mild effect on the self-normalized observables in the range of multiplicities studied at ALICE, and for this reason the two-Pomeron fusion mechanism can describe reasonably well the experimentally observed multiplicity dependence.