Novel non-equilibrium phase transition caused by non-linear hadronic-quark phase structure

Abstract

We consider how the occurrence of first-order phase transitions in non-constant pressure differs from those at constant pressure. The former has shown the non-linear phase structure of mixed matter, which implies a particle number dependence of the binding energies of the two species. If the mixed matter is mixed hadron-quark phase, nucleon outgoing from hadronic phase and ingoing to quark phase probably reduces the system to a non-equilibrium state, in other words, there exists the imbalance of the two phases when deconfinement takes place. This novel non-equilibrium process is very analogous to the nuclear reactions that nuclei emit neutrons and absorb them under appropriate conditions. We present self-consistent thermodynamics in description for the processes and identify the microphysics responsible for the processes. The microphysics is an inevitable consequence of non-linear phase structure instead of the effect of an additional dissipation force. When applying our findings to the neutron star containing mixed hadron-quark matter, it is found that the newly discovered energy release might strongly change the thermal evolution behavior of the star.

Properties of strange quark matter and strange quark stars

“…Currently, the only pulsars whose masses are larger than 2 M are PSR J0740+6620 (2.14 +0. 10 −0.09 M ) [21] and PSR J2215+5135 (2.27 +0. 17 −0.15 M ) [22].…”

“…Hence, there may be a possibility that the pulsars which are detected as neutron stars (NSs) may also be quark stars (QSs). SQM, if exist, may play a crucial role in the various remarkable fields such as hot and dense matter in heavy-ion collisions [4][5][6], compact stars structure [7], deconfinement phase transition [8][9][10][11][12][13] etc. The possibility for the existence or non-existence of various phases of compact stars is strongly constrained by the astrophysical data on pulsars.…”

Thermodynamic consistency, quark mass scaling, and properties of strange matter

“…Since its possible absolute stability was conjectured nearly thirty years ago [1], strange quark matter (SQM) has been playing an important role in many interesting fields, for example, the deconfinement phase transition [2][3][4][5][6][7], the hot and dense matter in heavy ion collisions [8], the structure of compact stars [9], etc. Lumps of SQM, the so-called strangelets [10], or slets [11], may exist in cosmic rays [12], and some of them might be on the way to our Earth [13,14].…”

Timing and evolution of PSR B0950+08

“…As discussed in some former works (Yuan & Zhang 1999;Kang & Zheng 2007;Zheng et al 2014), deconfinement heating is also an effective heating mechanism for older but warm pulsars. The heat generation of neutron stars containing mixed hadron-quark phase are calculated.…”

“…The heat generation of neutron stars containing mixed hadron-quark phase are calculated. The mean value of heat per baryon is around 0.1MeV, which is one order of magnitude higher than that of chemical heating (Zheng et al 2014). Further studies of interior structure and equation of state of neutron star coupled with thermal evolution could help us to gain more information about the thermal emission from pulsars.…”