Medium effects on the electrical conductivity of a hot pion gas

Abstract

The electromagnetic response of an interacting system of pions has been studied at finite temperature. The corresponding transport parameter i.e. electrical conductivity has been estimated by solving the relativistic transport equation in presence of a finite electric field employing the Chapman-Enskog technique where the collision term has been treated in the relaxation time approximation. The scattering amplitudes of charged pions modeled by ρ and σ meson exchange using an effective Lagrangian have been obtained at finite temperature by introducing self-energy corrections in the thermal propagators in the real time formalism. The temperature behavior of electrical conductivity for a hot pion gas shows significant quantitative enhancement due to the inclusion of medium effects in scattering.

Electrical conductivity and relaxation via colored noise in a hadronic gas

“…6 of the recent Ref. [59]. In that plot, our result (similar to Greif et al line) is close to other approaches with slightly different interaction, e.g.…”

“…The use of medium-modified interactions would also have influence on the transport coefficients. However, this would entail a large modification in the structure of the SMASH code, and the expected variation of σ el /T is expected to be of the order of ∼ 20% [59] for the top temperatures considered here (and less than ∼ 5% at T = 100 MeV). The results are presented in Fig.…”

“…This coefficient was computed in hadronic kinetic theory [27], partonic transport models [39,40], off-shell transport and dynamical quasiparticle models [41][42][43][44], holography [45][46][47], lattice QCD [29,[48][49][50], Dyson-Schwinger calculations [51], in the Polyakov-extended quarkmeson model [52], semianalytic calculations within perturbative QCD [53][54][55], and also taking into account strong magnetic fields [56,57]. Closer to the systems we are considering in this work we mention semianalytical calculations in a pion gas using chiral perturbation theory with and without unitarization [33,58], in a pion gas using a sigma model with and without mediummodified interactions [59], in a sigma model with baryon interactions [60], and in resonance gas models [27,61].…”

Electrical conductivity of hot Abelian plasma with scalar charge carriers

“…The electrical conductivity of such a plasma was considered in Refs. [42][43][44][45][46][47][48][49]. In contrast to our results, the conductivity of the pion gas decreases with temperature and reaches its minimal value in the vicinity of the phase transition.…”

“…In Refs. [42][43][44][45][46][47][48][49], the electric conductivity of such a plasma was calculated by the variety of methods, including Kubo relations, kinetic approach, chiral perturbation theory etc. However, the lightest scalars, pions, have the mass m π = 138 MeV which is of the same order as the phase transition temperature T c 150 MeV.…”