相关论文: Soft photons and hard thermal loops
The hard photon productions from bremsstrahlung and annihilation with scattering that arise at two loop level are estimated from a chemically non-equilibrated quark gluon plasma using the frame work of thermal field theory. Although, the…
We present a unified description of the high temperature phase of QCD, the so-called quark-gluon plasma, in a regime where the effective gauge coupling $g$ is sufficiently small to allow for weak coupling calculations. The main focuss is…
Working to all orders in dimensionally-regularized QCD, we study the radiation of a photon whose energy is much lower than that of external partons, but much larger than the masses of some quarks. We argue that the conventional soft photon…
We investigate photon production in a scenario of quark-gluon plasma formation in proton-proton scattering at 7 TeV. It is shown that thermal photon yields increase quadratically with the charged particle multiplicity. This gives an…
Within the Closed Time Path Formalism of Thermal Field Theory we calculate the hard photon emission rate as well as the collisional energy-loss rate for a quark-gluon plasma away from chemical equilibrium. Mass singularities are shown to be…
We evaluate the bremsstrahlung production of low mass dileptons and soft photons from equilibrating and transversely expanding quark gluon plasma which may be created in the wake of relativistic heavy ion collisions. We use initial…
In this paper we study the hard-thermal-loop effective theory at next-to-leading order. Standard power-counting predicts that a large number of diagrams, including 2-loop diagrams, may need to be calculated. In all of the calculations that…
We compute the pressure of a finite density quark-gluon plasma at zero temperature to leading order in hard-thermal-loop perturbation theory, which includes the fermionic excitations and Landau damping. The result is compared with the…
The electromagnetic emissivity from QCD media away from equilibrium is studied in the framework of closed time path thermal field theory. For the dilepton rate a nonequilibrium mesonic medium is considered applying finite temperature…
We calculate the thermodynamic functions of a quark-gluon plasma for general N_c and N_f to three-loop order using hard-thermal-loop perturbation theory. At this order, all the ultraviolet divergences can be absorbed into renormalizations…
We compute the momentum diffusion coefficient of a nonrelativistic heavy quark in a hot QCD plasma, to next-to-leading order in the weak coupling expansion. Corrections arise at O(g); physically they represent interference between…
This talk reviews the status of QCD calculations of photon and dilepton production rates in a Quark-Gluon plasma. Theses rates are known to order ${\cal O}(\alpha_s)$. Their calculations involve various resummations to account for well…
Soft photons produced in heavy ion collisions are an important tool for probing the properties of the quark-gluon plasma. It is therefore crucial to understand the background - soft photons produced in elementary collisions. Low theorem…
We study the emission of soft photons coupling to high energy fixed angle scattering processes at first order in the electromagnetic coupling but to all loop orders in a class of theories without soft divergences, including massive and…
We calculate the order \alpha_s finite temperature correction to dilepton production in quark-gluon plasma arising from the two-loop photon self-energy diagrams for high invariant mass M >> T.
This paper investigates the electromagnetic production of lepton pairs with low transverse momentum in relativistic heavy ion collisions. We estimate the initial photons' transverse momentum contributions by employing models where the…
It is believed that a novel state of matter - Quark Gluon Plasma (QGP) will be transiently produced if normal hadronic matter is subjected to sufficiently high temperature and/or density. We have investigated the possibility of QGP…
In this talk, I review new developments of QCD calculations of photon and dilepton production rates in a Quark-Gluon plasma. All the rates are now known up to $O(\alpha_s)$ both for photons and dileptons, thanks to the resummation of…
We consider the factorization and resummation of soft and Coulomb gluons for pair-production processes of heavy coloured particles at hadron colliders, and discuss: the construction of a colour basis that diagonalizes the leading soft…
Accurate knowledge of the thermodynamic properties of zero-temperature, high-density quark matter plays an integral role in attempts to constrain the behavior of the dense QCD matter found inside neutron-star cores, irrespective of the…