Nuclear-matter equation of state with consistent two- and three-body perturbative chiral interactions

Abstract

We compute the energy per particle of infinite symmetric nuclear matter from chiral N 3 LO (nextto-next-to-next-to-leading order) two-body potentials plus N 2 LO three-body forces. The low-energy constants of the chiral three-nucleon force that cannot be constrained by two-body observables are fitted to reproduce the triton binding energy and the 3 H-3 He Gamow-Teller transition matrix element. In this way, the saturation properties of nuclear matter are reproduced in a parameter-free approach. The equation of state is computed up to third order in many-body perturbation theory, with special emphasis on the role of the third-order particle-hole diagram. The dependence of these results on the cutoff scale and regulator function is studied. We find that the inclusion of threenucleon forces consistent with the applied two-nucleon interaction leads to a reduced dependence on the choice of the regulator only for lower values of the cutoff.

Spin-polarized neutron-rich matter at different orders of chiral effective field theory

“…where Λ < ∼ 500 MeV is associated with the onset of favorable perturbative properties [37,38]. Although designed to reproduce similar N N scattering phase shifts, N N potentials with different regulator functions will yield different predictions in the nuclear many-body problem due to their different off-shell behavior.…”

“…Estimates of theoretical uncertainties [32] for calculations of the equation of state of nuclear and neutron matter have largely focused on varying the low-energy constants and resolution scale at which nuclear dynamics are probed [33][34][35][36][37][38]. In a recent work [40], we layed the foundations for order-by-order calculations of nuclear many-body systems by presenting consistent NLO and N 2 LO chiral nuclear forces whose relevant short-range three-nucleon forces (3NF) are fit to A = 3 binding energies and the lifetime of the triton [39].…”

Asymmetric nuclear matter based on chiral two- and three-nucleon interactions

“…In future work, we will study the order-by-order convergence in the many-body expansion by including also particlehole contributions (see also Ref. [14]). We emphasize that Hamiltonian 6* (see Table I) does not influence these uncertainty estimates.…”

“…For symmetric matter it was found that low-momentum NN plus 3N interactions are capable to predict realistic saturation properties, with 3N forces fit only to few-body data [7], whereas neutron matter was found to be perturbative [8]. In subsequent studies, symmetric matter and neutron matter were also investigated based on chiral EFT interactions within the self-consistent Green's function framework [9,10], using coupled-cluster theory [11,12], with in-medium chiral perturbation theory [13] and in many-body perturbation theory [14]. Furthermore, the development of novel local chiral NN forces opened the way to first Quantum Monte Carlo studies of neutron matter based on chiral EFT interactions [15][16][17][18].…”

Role of Three-Nucleon Forces in Neutron-Rich Nuclei Beyond 132Sn

“…The regulator dependence of chiral potentials in many-body systems has been recently investigated in both neutron and nuclear infinite matter [14,15], where the NNN potential has been explicitly taken into account. In particular, in [14] it has been evidenced the crucial role of the NNN potential in order to provide the cutoff independence in infinite neutron matter.…”