Related papers: Pion gas viscosity at low temperature and density
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…
The density corrections, in terms of the isospin chemical potential $\mu_I$, to the mass of the pions are studied in the framework of the SU(2) low energy effective chiral lagrangian. The pion decay constant $f_{\pi}(T, \mu_{I})$ is also…
A gravity-scalar model in 5-dim. Riemann space is adjusted to the thermodynamics of SU(3) gauge field theory in the temperature range 1 - 10 $T/T_c$ to calculate holographically the bulk viscosity in 4-dim. Minkowski space. Various settings…
Following the Gauge Theory Bootstrap method proposed in our previous work [arXiv:2309.12402], we compute pion scattering phase shifts for all partial waves with angular momentum $\ell\le 3$ up to 2 GeV and calculate the low energy $\chi$PT…
We evaluate the pion mass in finite volume to two loops within Chiral Perturbation Theory. The results are compared with a recently proposed extension of the asymptotic formula of Luscher. We find that contributions, which were neglected in…
The relation of the shear viscosity coefficient to the recently introduced transport rate is derived within relativistic kinetic theory. We calculate the shear viscosity over entropy ratio \eta/s for a gluon gas, which involves elastic gg->…
The speed of cool pions in the chiral limit is analytically computed at low temperature within the imaginary time formalism to two loop order. This evaluation shows a logarithmic dependence in the temperature where the scale within the…
A two-dimensional strongly-coupled dusty plasma is modeled using Langevin and frictionless molecular dynamical simulations. The static viscosity $\eta$ and the wave-number-dependent viscosity $\eta(k)$ are calculated from the microscopic…
We computed the pole masses and decay constants of $\pi$ and $\rho$ meson at finite temperature in the framework of Dyson-Schwinger equations and Bethe-Salpeter equations approach. Below transition temperature, pion pole mass increases…
CERN COMPASS plans measurements of gamma-pi and gamma-K interactions using 50-280 GeV pion (kaon) beams and a virtual photon target. Pion (kaon) polarizabilities and radiative transitions will be measured via Primakoff effect reactions such…
We derive microscopic expressions for the bulk viscosity, shear viscosity and thermal conductivity of a quantum degenerate Bose gas above $T_C$, the critical temperature for Bose-Einstein condensation. The gas interacts via a contact…
The first part of this thesis focuses on the production of thermal dileptons from a hadronic gas at finite temperature. The rates are calculated by an expansion in Pion density and constrained by broken chiral symmetry and vacuum…
We consider the Dirac field in polar formulation, showing that when torsion is taken in effective approximation the theory has the thermodynamic properties of a van der Waals gas, that when the limit of zero chiral angle is taken the theory…
The shear viscosity of quark gluon plasma is customarily estimated in the literature using kinetic theory, which, however, is well known to break down for dense interacting systems. Here we propose an alternative theoretical approach based…
We study the role of viscosity in the early stages of relativistic heavy ion collisions. We investigate the role of viscosity on the chemical equilibration of a parton gas. In the presence of viscosity the lifetime of the system is…
In this work pion and kaon condensation in the framework of chiral perturbation theory is studied. I consider a system at vanishing temperature with nonzero isospin chemical potential and strangeness chemical potential; meson masses and…
The pion number fluctuations are considered in the system of pions and large mass fireballs decaying finally into pions. A formulation which gives an extension of the model of independent sources is suggested. The grand canonical and…
Employing new precision data of the equation of state of the SU(3) Yang-Mills theory (gluon plasma) the dilaton potential of a gravity-dual model is adjusted in the temperature range $(1 - 10) T_c$ within a bottom-up approach. The ratio of…
We apply the escape-rate formalism to compute the shear viscosity in terms of the chaotic properties of the underlying microscopic dynamics. A first passage problem is set up for the escape of the Helfand moment associated with viscosity…
Soft-pion theorems are used to show how chiral symmetry constrains the contributions of low-momentum pions to the quark condensate, the pion decay constant and hadron masses, all of which have been proposed as signals of partial restoration…