2007/10/30 by L.-W. Siu, L. -W. Siu, T.T.S. Kuo +2
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Nuclear physics research studies #Quantum, superfluid, helium dynamics #nucl-th
paper · pdf · doi:10.1103/physrevc.77.034001
published as Phys.Rev.C77:034001,2008 · 9 pages, 7 figures
arxiv created 2007/10/30 · openalex publication_date 2008/03/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study neutron matter at and near the unitary limit using a low-momentum ring diagram approach. By slightly tuning the meson-exchange CD-Bonn potential, neutron-neutron potentials with various 1S0 scattering lengths such as as=\ensuremath-12070 fm and +21 fm are constructed. Such potentials are renormalized with rigorous procedures to give the corresponding as-equivalent low-momentum potentials Vlow-k, with which the low-momentum particle-particle hole-hole ring diagrams are summed up to all orders, giving the ground state energy E0 of neutron matter for various scattering lengths. At the limit of as\ensuremath→\ifmmode±\else\textpm\fi\ensuremath∞, our calculated ratio of E0 to that of the noninteracting case is found remarkably close to a constant of 0.44 over a wide range of Fermi-momenta. This result reveals an universality that is well consistent with the recent experimental and Monte Carlo computational study on low-density cold Fermi gas at the unitary limit. The overall behavior of this ratio obtained with various scattering lengths is presented and discussed. Ring-diagram results obtained with Vlow-k and those with G-matrix interactions are compared.