Optimized Chiral Nucleon-Nucleon Interaction at Next-to-Next-to-Leading Order

Abstract

We optimize the nucleon-nucleon interaction from chiral effective field theory at next-to-next-to-leading order (NNLO). The resulting new chiral force NNLO(opt) yields χ(2)≈1 per degree of freedom for laboratory energies below approximately 125 MeV. In the A=3, 4 nucleon systems, the contributions of three-nucleon forces are smaller than for previous parametrizations of chiral interactions. We use NNLO(opt) to study properties of key nuclei and neutron matter, and we demonstrate that many aspects of nuclear structure can be understood in terms of this nucleon-nucleon interaction, without explicitly invoking three-nucleon forces.

Infrared extrapolations for atomic nuclei

“…This interaction has been optimized to scattering data of the nucleonnucleon system and deuteron bound-state properties. It is similar in quality to the chiral nucleon-nucleon interaction NNLO opt [31], which was optimized with respect to phase shifts. Figure 3 shows the CCSD ground state energies for 16 O as a function of L eff (left figure) and Ω (right figure) for model spaces with N = 8, 10, 12.…”

Comparative study of three-nucleon force models in nuclear matter

“…The important role played by the three-nucleon forces (TNFs) has been widely pointed out both in finite nuclei and nuclear matter calculations (see, e.g., [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] and references therein). First indications for the inclusion of a TNF in the nuclear Hamiltonian arose from the discrepancy between the results of the 3 H binding energy using different nucleonnucleon (NN) potentials and its experimental value.…”

Dipole response in neutron-rich nuclei within self-consistent approaches using realistic potentials

“…[21,22], while V ρ is a corrective repulsive, density dependent, two-body potential with a coupling constant C ρ . This force, introduced to simulate a three-body contact force [26], improves the description of bulk properties in closed-shell nuclei [27] and yields more realistic single-particle spectra and multipole-nuclear responses [19,20].…”

“…More recently, we performed analogous selfconsistent (Q)TDA and (Q)RPA studies by making direct use of a recently determined chiral potential, whose parameters were optimized so as to minimize the effects of the three-body forces [21]. This potential was adopted for 132 Sn in [22] and found to yield a much more compact single particle spectrum compared to V lowk and, consequently, to produce a dipole strength distribution much closer to the region of observation of the GDR peak.…”