title: Improved quantum hard-sphere ground-state equations of state.
abstract: The London ground-state energy formula as a function of number density for a system of identical boson hard spheres, corrected for the reduced mass of a pair of particles in a "sphere-of-influence" picture, and generalized to fermion hard-sphere systems with two and four intrinsic degrees of freedom, has a double-pole at the ultimate regular (or periodic, e.g., face-centered-cubic) close-packing density usually associated with a crystalline branch. Improved fluid branches are constructed based upon exact, field-theoretic perturbation-theory low-density expansions for many-boson and many-fermion systems, extrapolated to intermediate densities via Padé and other approximants, but whose ultimate density is irregular or random closest close-packing as suggested in studies of a classical system of hard spheres. Results show substantially improved agreement with the best available Green-function Monte Carlo and diffusion Monte Carlo simulations for bosons, as well as with ladder, variational Fermi hypernetted chain, and so-called L -expansion data for two-component fermions.
authors.affiliation: Department of Physics, Washington University, St. Louis, Missouri 63130, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Solís
authors.forename: M
authors.initials: M
authors.lastname: de Llano
authors.forename: J W
authors.initials: JW
authors.lastname: Clark
authors.forename: George A
authors.initials: GA
authors.lastname: Baker