From the lightest nuclei to the equation of state of asymmetric nuclear matter with realistic nuclear interactions

We present microscopic calculations of light and medium mass nuclei and the equation of state of symmetric and asymmetric nuclear matter using different nucleon-nucleon interactions, including a new Argonne version that has the same spin-isospin structure as local chiral forces at next-to-next-to-leading order. The calculations are performed using auxiliary field diffusion Monte Carlo (AFDMC) combined with an improved variational wave function and sampling technique. The AFDMC method can now be used to successfully calculate the energies of very light to medium mass nuclei as well as the energy of isospin-asymmetric nuclear matter, demonstrating microscopically the quadratic dependence of the energy on the symmetry energy.

Figure 1

The energy per nucleon of symmetric nuclear matter obtained using the Argonne ${\mathrm{AV}6}^{\prime }$ and ${\mathrm{AV}7}^{\prime }$ interactions, see the text for details. The blue diamond indicates the hypothetical saturation point of nuclear matter.

Figure 2

Energy per nucleon of isospin asymmetric nuclear matter calculated using the ${\mathrm{AV}6}^{\prime }$ potential as a function of the proton concentration. Green squares represent the AFDMC results and red circles the ones in which finite-size corrections are included. The numbers in parenthesis indicate the number of protons and neutrons considered in the simulations.