Quantum Monte Carlo calculations ofA=9,10nuclei

Abstract

We report on quantum Monte Carlo calculations of the ground and low-lying excited states of $A=9,10$ nuclei using realistic Hamiltonians containing the Argonne ${v}_{18}$ two-nucleon potential alone or with one of several three-nucleon potentials, including Urbana IX and three of the new Illinois models. The calculations begin with correlated many-body wave functions that have an $\ensuremath{\alpha}$-like core and multiple p-shell nucleons, $\mathrm{LS}$-coupled to the appropriate ${(J}^{\ensuremath{\pi}};T)$ quantum numbers for the state of interest. After optimization, these variational trial functions are used as input to a Green's function Monte Carlo calculation of the energy, using a constrained path algorithm. We find that the Hamiltonians that include Illinois three-nucleon potentials reproduce ten states in ${}^{9}\mathrm{Li},$ ${}^{9}\mathrm{Be},$ ${}^{10}\mathrm{Be},$ and ${}^{10}\mathrm{B}$ with an rms deviation as little as 900 keV. In particular, we obtain the correct ${3}^{+}$ ground state for ${}^{10}\mathrm{B},$ whereas the Argonne ${v}_{18}$ alone or with Urbana IX predicts a ${1}^{+}$ ground state. In addition, we calculate isovector and isotensor energy differences, electromagnetic moments, and one- and two-body density distributions.