Entropy and Equation of state for dense hot quark matter and its effect on compact quark stars

Dey et al. [1] derived an equation of state (EOS) for matter in strange stars (SS from hereon) with quark masses showing chiral symmetry restoration (CSM) and an interquark potential which (i) has asymptotic freedom built into it, (ii) shows confinement at zero density (ρB = 0) and deconfinement at high ρB. This EOS gives a stable configuration for chargeless, β-stable quark matter. The SS derived from this EOS fits into the empirical mass -radius (M-R) relations of some stars constraining the CSM parameters [1, 2, 3]. In the present paper we extend the calculation to include high temperatures upto T = 10 MeV ≡ 1.16× 10 K where the quark gas is still degenerate and find that the empirical M-R relation, derived from astrophysical data, is still satisfied. The EOS is tabulated for T = 10 MeV . The entropy is calculated and matches onto that calculated from hadronic models thus supporting the idea that the quark-hadron transition may be continuous. (1) Dept. of Physics, Presidency College, Calcutta 700 073, India (2) Azad Physics Centre, Dept. of Physics, Maulana Azad College, Calcutta 700 013, India (3) Abdus Salam ICTP, Trieste, Italy (4) Department of Physics, Burdwan University, Burdwan 713104, India. † permanent address; 1/10 Prince Golam Md. Road, Calcutta 700 026, India, e-mail : [email protected] ** Suported by DST Grant no. SP/S2/K18/96, Govt. of India.