Related papers: Dileptons from Disoriented Chiral Condensates
We suggest two methods for the detection of the formation of disoriented chiral condensates in heavy ion collisions. We show that the variance in the number of charged pions (in a suitable range of momentum space) provides a signature for…
The traditional calculation of dilepton yields from bremsstrahlung relies on the assumption that electromagnetic and strong processes factorize. We argue that this assumption, embodied by the soft photon approximation, cannot hold true for…
It is demonstrated that the presence of a phase transition in heavy ion collisions, at beam energies that probe dense QCD matter, leads to a significant enhancement of the dilepton yield per produced pion due to the extended emission time.…
We report on recent work relating the medium effects observed in dilepton spectra in heavy-ion collisions to potential signals of chiral symmetry restoration. The key connection remains the approach to spectral function degeneracy between…
Assuming that gluon condensates are important even above the deconfining phase transition, we develop a model for the dilepton yield from a quark gluon plasma. Using a simple fire ball description of a heavy ion collision, and various…
The production of dileptons is studied within a hadronic transport model. We investigate the sensitivity of the dilepton spectra to the initial configuration of the hadronic phase in a ultrarelativistic heavy ion collision. Possible in…
The possible chiral phase transition in high energy heavy-ion collisions may lead to the formation of a disoriented chiral condensate (DCC). However, the existence of many uncorrelated small domains in the rather large interaction volume…
We discuss a dynamical mechanism of pion production from disoriented chiral condensates (DCC). It leads to an explosive production of pions via the parametric amplification mechanism, which is similar to the reheating mechanism in…
We study the various stages of the evolution of chiral condensates disoriented via the ``baked-alaska'' mechanism, in which the condensates are described as the products of external sources localized on the light cone. Our analysis is based…
We analyze the dilepton emission rates from the hot pion gas confined to a finite space-time volume. Two models of pion(+) pion(-) annihilation to dileptons are under consideration. The first model mimics an extreme influence of the dense…
We use QCD kinetic theory to compute dilepton production coming from the pre-equilibrium phase of the Quark-Gluon Plasma created in high-energy heavy-ion collisions. We demonstrate that the dilepton spectrum exhibits a simple scaling in…
We have investigated the phase transition and disoriented chiral condensate domain formation in linear sigma model. Solving the Langevin equation for the linear $\sigma$ model, we have shown that for zero mass pions the fields undergo phase…
The dilepton invariant mass spectrum measured in heavy-ion collisions includes contributions from important QGP probes such as thermal radiation and the quarkonium ($J/\psi$, $\psi'$ and $\Upsilon$) states. Dileptons coming from hard $q…
Fluctuations in the ratio of neutral to charged pions arising due to formation of disoriented chiral condensates (DCC) are discussed using the Phi-measure. The properties of the measure for various cases of DCC and non-DCC are discussed.…
This work calculates the first correction to the leading order q\={q} dilepton production rates due to shear viscosity in an expanding gas. The modified rates are integrated over the space-time history of a viscous hydrodynamic simulation…
The production of dileptons with an invariant mass in the range 1 GeV < M < 5 GeV provides unique insight into the approach to thermal equilibrium in ultrarelativistic nucleus-nucleus collisions. In this mass range, they are produced…
We consider the thermal emission rate of dileptons from a QCD plasma in the small invariant mass ($Q^2 \sim \gs^2 T^2$) but large energy ($q^0 \gsim T$) range. We derive an integral equation which resums multiple scatterings to include the…
We analyse the extension of Chiral Perturbation Theory to describe a meson gas out of thermal equilibrium. For that purpose, we let the pion decay constant be a time-dependent function and work within the Schwinger-Keldysh contour…
We study the dynamics of the chiral phase transition expected during the expansion of the quark-gluon plasma produced in a high energy hadron or heavy ion collision, using the $O(4)$ linear sigma model in the mean field approximation.…
We show that an event-by-event fluctuation of the ratio of neutral pions or resulting photons to charged pions can be used as an effective probe for the formation of disoriented chiral condensates. The fact that the neutral pion fraction…