Speaker
Description
Dielectrons from open charm hadron decays provide a promising probe of heavy-quark interaction with the quark-gluon plasma (QGP) in relativistic heavy-ion collisions, and meanwhile constitute a crucial background of the invariant mass spectra of dielectrons from which the temperature of the QGP is extracted. So far, effects of medium modification of heavy quarks on dielectron spectra have been rarely investigated. In this work, we use a linear Boltzmann transport model to describe heavy quark scatterings with the QGP, which incorporates both Yukawa and string interactions. By converting heavy quarks into heavy flavor hadrons via a hybrid fragmentation-coalescence model and further decaying them into electrons via PYTHIA, we study the angular correlations of dielectrons and their invariant mass spectra in heavy-ion collisions at RHIC and LHC energies. Our results show that the angular correlations of $e^+e^-$ pairs are sensitive to the interaction mechanisms between heavy quarks and the QGP. In particular, the energy loss is effective in suppressing the away-side peak of their angular distributions, while the collective flow of the QGP enhances the near-side peak. Additionally, we find that both energy loss of heavy quarks and their hadronization mechanism affect the invariant mass spectra of dileptons, which can further lead to a sizable systematic uncertainty of the value of the QGP temperature extracted from the dilepton spectra.
