arXiv subjects
Publications and source records attributed to O. P. Pavlenko.
The relation of the thermal dilepton signal from deconfined matter, resulting in central ultra-relativistic heavy-ion collisions at RHIC and LHC energies, to the background yields from the Drell-Yan process and correlated semileptonic decays of open charm and bottom mesons is analyzed. We demonstrate that very stringent kinematical cuts offer a chance to identify the thermal signal in the continuum region.
We consider the intermediate mass continuum of dileptons (between $ϕ$ and $J/ψ$) in ultrarelativistic heavy--ion collisions. The thermal signal depends essentially on thermodynamic state parameters of the hottest parton stage as $(τ_iλ^q_iT_i^3)^2$ convoluted with an involved detector acceptance function. A refined analysis of the transverse pair momentum spectrum at fixed dilepton transverse mass can reveal the maximum temperature of parton matter.
In ultrarelativistic heavy-ion collisions at $\sqrt{s} >$ 20 (120) A$\cdot$GeV a copious production of charm (bottom) production sets in which, via correlated semileptonic $D \bar D$ ($B \bar B$) decays, gives rise to a dilepton yield at invariant mass $M \approx$ 2 -- 3 GeV in excess of the Drell-Yan yield and the thermal dilepton signal from deconfined matter as well. We show that appropriate single-electron transverse momentum cuts (suitable for ALICE at LHC) cause a threshold like behavior of the dilepton spectra from heavy-quark meson decays and the Drell-Yan process and can allow to observe a thermal dilepton signal from hot deconfined matter.
We analyze the opportunity to observe thermal dileptons emitted off deconfined matter resulting in heavy-ion collisions at RHIC and LHC energies. Special kinematical conditions provided by the detector systems PHENIX and ALICE, and the so-called $M_\perp$ scaling behavior of thermal dilepton spectra are taken into account. Our considerations include energy loss effects of the fast heavy quarks in deconfined matter, which for themselves can help to identify the creation of a hot and dense parton medium. Due to a threshold like effect for decay leptons we find a window at large transverse pair momentum and fixed transverse mass where the thermal signal can exceed the background of dileptons from correlated semileptonic decays of charm and bottom mesons.
Relying on the Luttinger-Ward theorem we derive a thermodynamically selfconsistent and scale independent approximation of the thermodynamic potential for the scalar $ϕ^4$ theory in the tadpole approximation. The resulting thermodynamic potential as a function of the temperature is similar to the one of the recently proposed screened perturbation theory.
The spectra of lepton pairs from correlated open charm and bottom decays in ultrarelativistic heavy-ion collisions are calculated. Our approach includes energy loss effects of the fast heavy quarks in deconfined matter which are determined by temperature and density of the expanding parton medium. We find a noticeable suppression of the initial transverse momentum spectrum of heavy quarks due to the energy loss within the central rapidity covered by the PHENIX detector system. As a result the dilepton yields from correlated decays of heavy quarks are in the same order of magnitude as the Drell-Yan signal.
The spectra of lepton pairs from correlated open charm and bottom decays in ultrarelativistic heavy-ion collisions are calculated. Our approach includes energy loss effects of heavy quarks in deconfined matter which are determined by temperature and density of the expanding parton medium. We find a noticeable suppression of the initial transverse momentum spectrum of heavy quarks due to the energy loss at LHC conditions. Within the central rapidity covered by the ALICE detector system, the dominant contribution from bottom decays to the high invariant mass dielectron spectrum is predicted.