Three-body forces and neutron star structure

The maximum and minimum mass of protoneutron stars in the Brueckner theory

“…In the BBG approach, the TBF is reduced to a density-dependent two-body force by averaging over the position of the third particle, assuming that the probability of having two particles at a given distance is reduced according to the two-body correlation function. The corresponding EOS reproduces the nuclear matter saturation point correctly (Baldo et al 1997;Zhou et al 2004;Li et al 2008a) and fulfills several requirements from the nuclear phenomenology. In all calculations presented in this paper we used the Argonne V 18 nucleon-nucleon potential (Wiringa et al 1995) along with the phenomenological Urbana TBF.…”

“…(ii) The addition of phenomenological three-body forces (TBF) based on the Urbana model (Carlson et al 1983;Schiavilla et al 1986), permitted improving the agreement to a large extent with the empirical saturation properties (Baldo et al 1997;Zhou et al 2004;Li et al 2006Li et al , 2008a. (iii) The Brueckner-Hartree-Fock (BHF) approach has been extended in a fully microscopic and self-consistent way to describe nuclear matter also containing hyperons (Schulze et al 1995.…”

Comparative study of three-nucleon force models in nuclear matter

“…To simplify the numerical calculations and following [50,51], in the present work we use central correlation functions g(i,j ) independent on spin and isospin. Moreover, it has been shown [52,53] that this central correlation functions, in which are included the main contributions of the 1 S 0 and 3 S 1 channels, are weakly dependent on the density, and can be approximated [50,52,53] by a Heaviside step function θ (r ij − r c ), with r c = 0.6 fm in all the considered density range. Note that the average procedure has to be performed for each term involved in the cyclic permutation in Eq.…”

The hadron-quark phase transition in neutron stars

“…For details, the reader is referred to Ref. [ 8]. We have extended the BHF approach in a fully microscopic and self-consistent way, in order to describe nuclear matter containing also hyperons [ 9].…”