Properties of vector mesons at finite temperature: Effective Lagrangian approach

Abstract

The properties of ρ-mesons at finite temperature (T ) are examined with an effective chiral lagrangian in which vector and axial-vector mesons are included as massive Yang-Mills fields of the chiral symmetry. It is shown that, at T 2 order, the effective mass is not changed but only the mixing effect in vector and axial-vector correlator appears.

Finite Temperature Effects on Electromagnetic Probes of Quark–Gluon Plasma

“…Here we would like to mention that the temperature dependence of the ρ-mass in a SU(2) L × SU(2) R chiral effective model, in the MYMA, has been calculated in Ref. 17. The effect observed here is somewhat more compared to what is obtained in Ref.…”

Vector and axial-vector mesons at finite temperature

“…One has the massive Yang-Mills [13] and the hidden gauge [14] formulations. Since these Lagrangians are built on the SU (2) × SU (2) flavor symmetry, they also produce no shift in the meson masses to O(T 2 ) [15,16]. However, the coefficients of T 4 quoted in these works must be incomplete, as they do not include two loop diagrams.…”

Electromagnetic effects in the pion dispersion relation at finite temperature

“…Their residues are meant to contribute also at OðT 2 Þ ∼ OðxM 2 R Þ via the ρ − a 1 mixing effect discussed in Sec. III [10,47,75], while the mass and width modifications of the spectral functions are expected to be of Oðe…”

“…These modifications might lead to important observable effects, as it is indeed the case with the ρð770Þ meson and its influence in the dilepton spectrum [10][11][12]17]. However, the temperature dependence of the masses of pions and other light mesons is usually not included in phenomenological analysis of hadron yields [8] despite the fact that the dispersion relation enters directly in the particle number distribution.…”

“…The hadron resonance gas (HRG) describes the system through the statistical ensemble of all free states thermally available and provides a good description both of lattice thermodynamical data and of experimental hadron yields, when some corrections due to interactions and lattice masses are accounted for [8,9]. On the other hand, effective chiral models including explicitly vector and axial-vector resonances have been successfully used to describe several hadron thermal properties relevant for observables such as the dilepton and photon spectra and ρ − a 1 mixing/degeneration at the chiral transition [10][11][12][13].…”