Properties of kaon at non-zero temperature and baryon chemical potential

Abstract

We investigate the spectroscopic properties of the strange particle kaon in the framework of hot and dense QCD. To this end, first, we find the perturbative spectral density, which is connected with both the temperature T and the baryon chemical potential mu(B). We include the non-perturbative operators as functions of temperature and baryon chemical potential up to mass dimension five. We perform the calculations in momentum space and use the quark propagator in the hot and dense medium. The numerical results at non-zero temperature and baryon chemical potential demonstrate that the mass of the particle rises considerably by increasing the baryon chemical potential at a fixed temperature (for both the zero and non-zero temperatures) up to approximately mu(B) = 0.4 GeV. After this point, it starts to fall by increasing the baryon chemical potential and it apparently vanishes at mu(B) = (1.03-1.15) GeV for finite temperatures: The point of apparent vanishing moves to lower baryon chemical potentials by increasing the temperature. At zero temperature, the mass reaches to roughly a fixed value at higher baryon chemical potentials. On the other hand, the decay constant decreases considerablywith respect to baryon chemical potential up to roughly mu(B) = 0.4 GeV, but after this point, it starts to increase in terms of the baryon chemical potential at finite temperatures. At T = 0, the decay constant reaches to a fixed value at higher chemical potentials, aswell. Regarding the dependence on the temperature we observe that, at fixed values of baryon chemical potentials, the mass and decay constant remain roughly unchanged up to T = 50 MeV and T = 70 MeV respectively, but after these points, the mass starts to fall and the decay constant starts to rise up to a critical temperature T = 155 MeV, considerably. It is also seen that the obtained results for the mass and decay constant at T = mu(B) = 0 are in good consistency with the existing experimental data. The observations are consistent with the QCD phase diagram in the T - mu(B) plane.