Variational calculations of few-body nuclei

Improved variational wave functions for use in microscopic studies of few-body nuclei are presented. The trial functions are constructed from pair-correlation operators, which include central, spin, isospin, tensor, and spin-orbit components, and triplet-correlation operators, which include components induced by three-nucleon potentials. Energy expectation values are calculated using Metropolis Monte Carlo integration. Variational parameter searches are made using energy differences to reduce the effect of statistical fluctuations on the choice of optimal trial functions. Results are reported for ground-state binding energies of ${}_{}{}^3{}_{}{}^{}\mathrm{H}$ and ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ using the Reid ${\mathit{v}}_8$ and Argonne ${\mathit{v}}_{14}$ two-nucleon potentials, and Argonne ${\mathit{v}}_{14}$ with the Tucson-Melbourne, Urbana VII, and Urbana VIII three-nucleon potentials. The variational binding energies are typically 3–4% above available Faddeev and Green’s-function Monte Carlo results. Nucleon density distributions and elastic electromagnetic form factors are also presented. Extension of these wave functions to larger nuclei such as ${}_{}{}^5{}_{}{}^{}\mathrm{He}$, ${}_{}{}^6{}_{}{}^{}\mathrm{He}$, and ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ is discussed.