Munshi G. Mustafa

Energy loss of charm quarks in the quark-gluon plasma : Collisional vs radiative losses

In considering the collisional energy loss rates of heavy quarks from hard light parton interactions, we computed the total energy loss of a charm quark for a static medium. For the energy range E{approx}5-10 GeV of charm quark, it proved to be almost the same order as that of radiative ones estimated to a first-order opacity expansion. The collisional energy loss becomes much more important for lower energy charm quarks, and this feature could be very interesting for the phenomenology of hadrons spectra. Using such collisional energy loss rates, we estimate the momentum loss distribution employing a Fokker-Planck equation and the total energy loss of a charm quark for an expanding quark-gluon plasma under conditions resembling the energies presently available at the BNL Relativistic Heavy Ion Collider. The fractional collisional energy loss is found to be suppressed by a factor of 5 as compared to the static case and does not depend linearly on the system size. We also investigate the heavy to light hadrons D/{pi} ratio at moderately large (5-10 GeV/c) transverse momenta and comment on its enhancement.

Radiative and Collisional Jet Energy Loss in the Quark-Gluon Plasma at the BNL Relativistic Heavy Ion Collider

We calculate and compare bremsstrahlung and collisional energy loss of hard partons traversing a quark-gluon plasma. Our treatment of both processes is complete at leading order in the coupling and accounts for the probabilistic nature of the jet energy loss. We find that the nuclear modification factor RAA for neutral π 0 production in heavy ion collisions is sensitive to the inclusion of collisional and radiative energy loss contributions while the averaged energy loss only slightly increases if collisional energy loss is included for parent parton energies E ≫ T . These results are important for the understanding of jet quenching in Au+Au collisions at 200 AGeV at RHIC. Comparison with data is performed applying the energy loss calculation to a relativistic ideal (3+1)-dimensional hydrodynamic description of the thermalized medium formed at RHIC.

Three-loop HTLpt thermodynamics at finite temperature and chemical potential

A bstractWe calculate the three-loop thermodynamic potential of QCD at finite temperature and chemical potential(s) using the hard-thermal-loop perturbation theory (HTLpt) reorganization of finite temperature and density QCD. The resulting analytic thermodynamic potential allows us to compute the pressure, energy density, and entropy density of the quark-gluon plasma. Using these we calculate the trace anomaly, speed of sound, and second-, fourth-, and sixth-order quark number susceptibilities. For all observables considered we find good agreement between our three-loop HTLpt calculations and available lattice data for temperatures above approximately 300 MeV.

Quenching of hadron spectra due to the collisional energy loss of partons in the quark-gluon plasma

We estimate the energy loss distribution and investigate the quenching of hadron spectra in ultrarelativistic heavy-ion collisions due to the collisional energy loss of energetic partons from hard parton collisions in the initial stage.

Susceptibilities and speed of sound from the Polyakov-Nambu-Jona-Lasinio model

We present the Taylor expansion coefficients of the pressure in quark number chemical potential

Radiative energy-loss of heavy quarks in a quark-gluon plasma

\mu_0=\mu_B / 3=\mu_u=\mu_d

Finite temperature meson correlation functions in HTL approximation

, for the strongly interacting matter as described by the PNJL model for two light degenerate flavours of quarks u and d. The expansion has been done upto eighth order in

Expanding quark - gluon plasmas: Transverse flow, chemical equilibration and electromagnetic radiation

\mu_0

Three-loop pressure and susceptibility at finite temperature and density from hard-thermal-loop perturbation theory

, and the results are consistent with recent estimates from Lattice. We have further obtained the specific heat

Quark number susceptibility in hard thermal loop approximation

C_V