Related papers: Dilepton from Disoriented Chiral Condensates
Using a semi-classical treatment of the linear sigma model, we simulate the dynamical evolution of an initially hot cylindrical rod endowed with a longitudinal Bjorken scaling expansion (a ``Bjorken rod''). The field equation is propagated…
We discuss the various physics aspects of hypothetical, coherent excitations of the pion field caused by spontaneously generated local distortions of the chiral order parameter. Such distortions, which may occur in the expansion of a hot…
Ultra-relativistic heavy-ion collisions are used to create a deconfined state of quarks and gluons, the quark-gluon plasma (QGP), similar to the matter in the early universe. Dileptons are a unique probe of the QGP. Being emitted during all…
An analysis of semileptonic decays of $B$ mesons with the emission of a single soft pion is presented in the framework of the heavy-quark limit using an effective Lagrangian which implements chiral and heavy-quark symmetries. The analysis…
It is thought that a region of pseudo-vacuum, where the chiral order parameter is misaligned from its vacuum orientation in isospin space, might occasionally form in high energy hadronic or nuclear collisions. The possible detection of such…
A new formalism to calculate the in-medium chiral condensate is presented. At lower densities, this approach leads to a linear expression. If we demand a compatibility with the famous model-independent result, then the pion-nucleon sigma…
We demonstrate that semiclassical fluctuations, their relaxation, and the chiral phase transition are automatically incorporated in the numerical simulations of the classical equations of motion in the linear $\sigma$-model when…
We study dilepton production in proton-proton, Cu+Cu as well as in Au+Au collisions at the center-of-mass energy 200 GeV per participating nucleon pair within an extended statistical hadronization model. In extension to earlier studies we…
Applying the effective amplitude, which is evidently consistent with general constraints from chiral symmetry, the pipi spectra in the relevant processes are analyzed, leading to a strong evidence for existence of the light sigma meson. It…
The effective field theory including the dissipative effect is developed based on the Caldeira-Leggett theory at the classical level. After the integration of the small field fluctuations considered as the field radiation, the…
Dilepton emission rates from a hadronic gas at finite temperature and baryon density are completely constrained by broken chiral symmetry in a density expansion. The rates can be expressed in terms of vacuum correlations which are measured…
We include effects of chiral symmetry and its restoration in the kinetic equations for baryon propagation and explore the consequences for $\eta$, $\pi^0$, $\rho$ and dilepton production in heavy-ion collisions at 1-2A GeV. Numerical…
We first review the calculations of low invariant mass dilepton production in relativistic heavy ion collisions, using effective hadronic Lagrangians. We go through some of the theoretical techniques used in this kinematical region and we…
The rate of emission of heavy dileptons from QGP is found without an assumption of its complete thermal equilibrium. We base on the real-time quantum field kinetic approach [1] and use the expansion up to the second order with respect to…
One of the main aims of present and upcoming high energy heavy ion collision experiments is to study new phases of matter at extreme temperature and density. It is expected that a nontrivial classical pion field configuration can…
Transport and hydrodynamical models used to describe the expansion stage of a heavy-ion collision at the CERN SPS give different dilepton spectrum even if they are tuned to reproduce the observed hadron spectra. To understand the origin of…
We present a unified description of the vector meson and dilepton production in elementary and in heavy ion reactions. The production of vector mesons ($\rho,\omega$) is described via the excitation of nuclear resonances ($R$). The…
We present a study of the $\pi\pi$ scattering amplitude in the $\sigma$ and $\rho$ channels at finite temperature and nuclear density within a chiral unitary framework. Meson resonances are dynamically generated in our approach, which…
It is possible that isospin violating dynamical effects are amplified due to coherence if a disoriented chiral condensate (or other source of a coherent pion state) is formed in a heavy ion collison. It is shown explicitly that altering the…
We use a simple QCD-based model to study particle production in S+Au collisions at 200 GeV/n. A requisite consistency is met for the hadronic observables (pi0 and pi- spectra) while pursuing estimates for e+e- production. Since radiative…