Correlations between heavy mesons and the creation of the charmonia, bottomonia, and $B_c$ mesons in high energy $pp$ collisions

Abstract

The different QCD processes, which can produce a heavy quark-antiquark ($Q\bar Q$) pair, induce different correlations between the heavy quarks. Employing the EPOS4HQ event generator we study the consequences of these correlations and compare the calculation with experimental results on open and hidden heavy flavour mesons, measured in proton-proton (pp) collisions at RHIC and LHC energies. We find that the measured correlations between heavy mesons are a direct image of the different production mechanisms, which contribute also in a different way to the transverse momentum distribution of open and hidden heavy flavour mesons. The latter are calculated in a Wigner density approach which also enables to reproduce quantitatively the measured $B_c$ spectra. This agreement allows conclusions on the spatial distribution of the heavy quark creation processes.