Lattice quantum chromodynamical approach to nuclear physics

We present an updated version (Nijm93) of the Nijmegen soft-core potential, which gives a much better description of the np data than the older version (Nijm78). The chi^2 per datum is 1.87. The configuration-space and momentum-space versions of this potential are exactly equivalent; a unique feature among meson-theoretical potentials. We also present three new NN potential models: a non-local Reid-like Nijmegen potential (NijmI), a local version (NijmII), and an updated regularized version (Reid93) of the Reid soft-core potential. These three potentials all have a nearly optimal chi^2 per datum and can therefore be considered as alternative partial-wave analyses. All potentials contain the proper charge-dependent one-pion-exchange tail. Fortran code for the potentials can be obtained via anonymous ftp from thef-nym.sci.kun.nl

We present a new high-quality nucleon-nucleon potential with explicit charge dependence and charge asymmetry, which we designate Argonne \(v_{18}\). The model has a charge-independent part with fourteen operator components that is an updated version of the Argonne \(v_{14}\) potential. Three additional charge-dependent and one charge-asymmetric operators are added, along with a complete electromagnetic interaction. The potential has been fit directly to the Nijmegen \(pp\) and \(np\) scattering data base, low-energy \(nn\) scattering parameters, and deuteron binding energy. With 40 adjustable parameters it gives a \(\chi^{2}\) per datum of 1.09 for 4301 \(pp\) and \(np\) data in the range 0--350 MeV.

We present a charge-dependent nucleon-nucleon (NN) potential that fits the world proton-proton data below 350 MeV available in the year of 2000 with a chi^2 per datum of 1.01 for 2932 data and the corresponding neutron-proton data with chi^2/datum = 1.02 for 3058 data. This reproduction of the NN data is more accurate than by any phase-shift analysis and any other NN potential. The charge-dependence of the present potential (that has been dubbed `CD-Bonn') is based upon the predictions by the Bonn Full Model for charge-symmetry and charge-independence breaking in all partial waves with J <= 4. The potential is represented in terms of the covariant Feynman amplitudes for one-boson exchange which are nonlocal. Therefore, the off-shell behavior of the CD-Bonn potential differs in a characteristic and well-founded way from commonly used local potentials and leads to larger binding energies in nuclear few- and many-body systems, where underbinding is a persistent problem.