Structure and tidal deformability of a hybrid star within the framework of the field correlator method

Abstract

The structure of hybrid stars within the nonperturbative framework of the field correlator method, extended to zero-temperature limit as a quark model, has been studied. For the hadronic sector, we have used the lowest-order constraint variational method by employing AV 18 two-body nucleon-nucleon interaction supplemented by the phenomenological Urbana-type three-body force. For an adapted value of the gluon condensate, G 2 = 0.006 GeV 4 , which gives the critical temperature of about T c ∼ 170 MeV, stable hybrid stars with a maximum mass of 2.04M ⊙ are predicted.The stability of hybrid star has been investigated for a wide range of gluon condensate value, G 2 , and quark-antiquark potential, V 1 . A hybrid equation of state fulfills the constraints on tidal deformability and hence on the radii of the stars, extracted from the binary GW170817. Moreover, tidal deformability for different chirp masses and different binary mass ratios of hybrid stars have been studied. The mass-radius relation satisfies the new constraint obtained from the neutron star interior composition explorer (NICER). A comprehensive analysis on the structure of a hybrid star and also its compactness, tidal Love number, and tidal deformability has been conducted for several parameter sets of the quark equation of state. The influence of different crustal equations of state on the mentioned quantities has been studied.Our calculations suggest the value of quark-antiquark potential, V 1 , to be around 0.08 GeV. The results achieved in this study are in strong concurrence with the other calculations reported on this subject.