Related papers: Density effects on the pion dispersion relation at…
We discuss various aspects of pion physics in the nuclear medium. We first study s-wave pion-nucleus interaction in connection with chiral symmetry restoration and quark condensate in the nuclear medium. We then adress the question of…
In order to study partial restoration of the chiral symmetry at finite density, we investigate the density corrections of the chiral condensate up to next-leading order of density expansion using the chiral Ward identity and an in-medium…
Vector Meson Dominance ideas together with a Finite Energy QCD sum rule allows for the determination of the $q^{2}$- and the $T$- dependence of the effective hadronic coupling constant $g_{\rho \pi \pi}$ in the space-like region. It turns…
Recent developments in low energy pion physics are reviewed, emphasizing the strength of dispersion theory in this context. As an illustration of the method, I discuss some consequences of the forward dispersion relation obeyed by the…
Pion dissociation in a medium of hot quark matter is studied. The decay width of pion is found to be large but finite at temperatures much higher than the so called critical temperature of chiral or deconfinement transition. Consequently,…
A method allowing analysis of the overpopulation of phase-space in heavy ion collisions in a model independent way is proposed within the hydrodynamic approach. It makes it possible to extract a chemical potential of thermal pions at freeze…
When the isospin chemical potential exceeds the pion mass, charged pions condense in the zero-momentum state forming a superfluid. Chiral perturbation theory provides a very powerful tool for studying this phase. However, the formalism that…
We study the behavior of the rho vector mass in the context of the almost baryon-free environment of an ultra-relativistic heavy-ion collision. We show that rho scattering within the hadronic phase of the collision leads to a temperature…
Within the framework of dispersion theory, we study the the processes $e^+e^-\to \phi(2170) \to \phi \pi\pi(K\bar{K})$. The strong pion-pion final-state interactions, especially the $K\bar{K}$ coupled channel in the $S$-wave, are taken into…
By measuring hadronic single-particle spectra and two-particle correlations in heavy-ion collisions, the size and dynamical state of the collision fireball at freeze-out can be reconstructed. I discuss the relevant theoretical methods and…
We estimate the shear and the bulk viscous coefficients for a hot hadronic gas mixture constituting of pions and nucleons. The viscosities are evaluated in the relativistic kinetic theory approach by solving the transport equation in the…
We give predictions for the partial wave amplitudes of pion photoproduction near threshold by means of dispersion relations at fixed t. The free parameters of this approach are determined by a fit to experimental data in the energy range…
The grand canonical ensemble formulation of the van der Waals equation of state that includes the effects of Bose statistics is applied to an equilibrium system of interacting pions. If the attractive interaction between pions is large…
We consider chiral perturbation theory for SU(2) at finite temperature $T$ in a constant magnetic background $B$. We compute the thermal mass of the pions and the pion decay constant to leading order in chiral perturbation theory in the…
We investigate the finite temperature behavior of the meson sector of an effective Lagrangian which describes nuclear matter. A method is developed for evaluating the logarithmic terms in the effective potential which involves expansion and…
A study of energy behavior of the pion spectra and interferometry scales is carried out for the top SPS, RHIC and LHC energies within the hydrokinetic approach. The latter allows one to describe evolution of quark-gluon and hadron matter as…
The thermodynamics with medium effects expressed by the dispersion relation of the temperature and density dependent particle mass is studied. Many previous treatments have been reviewed. A new thermodynamical treatment based on the…
In this talk, we report our recent work on the pion weak decay constant (F_pi) and pion mass (m_pi) using the nonlocal chiral quark model with the finite quark-number chemical potential (mu) taken into account. Considering the breakdown of…
We present the pion-pion elastic scattering amplitude at finite temperature to one-loop in Chiral Perturbation Theory. The thermal scattering amplitude properly defined allows to generalize the perturbative unitarity relation to the $T\neq…
We point out that, in analogy with spin waves in antiferromagnets, all parameters describing the real-time propagation of soft pions at temperatures below the QCD chiral phase transition can be expressed in terms of static correlators. This…