Vector meson masses in hot nuclear matter: the effect of quantum corrections

Abstract

The medium modification of vector meson masses is studied taking into account the quantum correction effects for the hot and dense hadronic matter. In the framework of Quantum Hadrodynamics, the quantum corrections from the baryon and scalar meson sectors were earlier computed using a nonperturbative variational approach through a realignment of the ground state with baryon-antibaryon and sigma meson condensates. The effect of such corrections was seen to lead to a softer equation of state giving rise to a lower value for the compressibility and, an increase in the in-medium baryonic masses than would be reached when such quantum effects are not taken into account. These quantum corrections arising from the scalar meson sector result in an increase in the masses of the vector mesons in the hot and dense matter, as compared to the situation when only the vacuum polarisation effects from the baryonic sector are taken into account.

Dilepton emission rates from hot hadronic matter

“…For the ω meson, the tensor coupling, being small as compared to the vector coupling to the nucleons [6], is neglected [21,22]. After carrying out the renormalization procedures for the vector self energies, the effective mass of the vector meson is obtained by solving the equation…”

“…The methodology was then generalized to consider hot nuclear matter [25] as well as to study hyperon-rich dense matter [26] relevant for neutron stars. The effect of vacuum polarisations on the vector meson properties [21] and on the static dilepton spectra [22] has also been recently studied. In the low invariant mass regime, the scalar meson contributions lead to considerable broadening the ω peak in the dilepton spectra as compared to RHA, which leads to smearing and ultimate disappearance of the ω peak at high densities [22].…”

Dmesons in asymmetric nuclear matter

“…The hadrons modified in the hot and dense hadronic medium resulting from heavy ion collision experiments, affect the experimental observables. E.g.,the dilepton spectra observed from heavy ion collision experiments at the SPS [1,2] are attributed to the medium modifications of vector mesons [3,4,5,6,7], and can not be explained by vacuum hadronic properties. The production of kaons and antikaons as well as their collective flow are attributed to the modifications of their spectral functions in the medium [4,8,9,10,11,12,13,14].…”

The DIELECTRIC FUNCTION EXCITED BY ΡNN TENSOR COUPLING IN NUCLEAR MATTER

“…The induced current mechanism has been introduced to explain the three extrema on the dielectric function curve, of which one is in the space-like region and the other two are in the time-like region. It points out that the tensor coupling contributes much more large amplitude than the vector coupling and plays a more important role on the time-like region compared with its effect on the space-like region.PACS number(s): 21.65.+f,11.10.Wx,13.75.Cs Keywords: Nuclear matter; Finite temperature field thoery; Nucleonnucleon interactionThe medium effects of the nuclear matter at finite temperature and/or density, such as the dispersion relation, the dielectric function (namely ε), the permeability and the nuclear effective mass, are very important facing the high energy physics today and excited a lot of investigations [1][2][3][4][5][6][7][8]. Among these, the dielectric property of strongly interacting matter (nuclear and quark matter) is a significant one, for it dominates the differences between the field in vacuum and in medium.…”

“…In many experiments and phenomenological theories such viewpoint has been proved correct [16,17]. The strong sensitivity of the ρ meson mass to the ρNN tensor coupling have also been investigated by some authors [8]. In order to carry on a quantitative calculation, the tensor coupling constant is included along with the vector coupling in the interactive Lagrangian:…”