Polarized neutron matter: A lowest order constrained variational approach

Abstract

In this paper, we calculate some of the polarized neutron matter properties, using the lowest order constrained variational method with the AV 18 potential and * Corresponding author † E-mail : bordbar@physics.susc.ac.ir ‡ Permanent address 1 employing a microscopic point of view. A comparison is also made between our results and those of other many-body techniques. 21.65.+f, 26.60.+c, 64.70.-p IntroductionPulsars are rapidly rotating neutron stars with strong surface magnetic fields in the range of 10 12 − 10 13 Gauss [1, 2, 3]. The physical origin of this magnetic field remains an open problem and there is still no general consensus regarding the mechanism to generate such strong magnetic fields in a neutron star. There exist several possibilities of the generation of the magnetic field in a neutron star, from the nuclear physics point of view, however, one of the most interesting and stimulating mechanisms which have been suggested is the possible existence of a phase transition to a ferromagnetic state at densities corresponding to the theoretically stable neutron stars and, therefore, of a ferromagnetic core in the liquid interior of such compact objects. Such a possibility has been studied by several authors using different theoretical approaches , but the results are still contradictory.Whereas some calculations, like for instance the ones based on Skyrmelike interactions predict the transition to occur at densities in the range (1 − 4)ρ 0 (ρ 0 = 0.16f m −3 ), others, like recent Monte Carlo [20] and Brueckner-Hartree-Fock calculations [21-23] using modern two-and three-body realistic interactions exclude such a transition, at least up to densities around five times ρ 0 . This transition could have important consequences for the evolution of a protoneutron star, in particular for the spin correlations in the medium which do

Spin-polarized states in neutron matter in a strong magnetic field

“…However, for the D1S Gogny force an antiferromagnetic phase transition happens in symmetric nuclear matter at the density 3.8̺ 0 [24]. On the other hand, for the models with the realistic NN interaction, no sign of spontaneous spin instability has been found so far at any isospin asymmetry up to densities well above ̺ 0 [25]- [31].…”

Microscopic study of 1S0 superfluidity in dilute neutron matter

“…al. [29,28,30]. It is under- as a function of wave number k, obtained with an effective pairing interaction determined from eq.…”

The Effect of a Density-Dependent Bag Constant on the Structure of a Hot Neutron Star with a Quark Core

“…In our calculations, the equation of state of hot nucleonic matter is computed using the lowest order constrained variational (LOCV) method [12][13][14][15][16][17][18][19]. The details of our calculations for the hadronic phase has been fully discussed in [11].…”