Exact Calculations of Light Nuclei Using Realistic Interactions

One of the principal goals of nuclear physics is to explain the properties and reactions of nuclei in terms of interacting nucleons (protons and neutrons). There are two fundamental aspects to this problem: (1) determining the interactions between nucleons, and (2) given the interactions (i.e., the Hamiltonian) making accurate calculations of many-nucleon systems. S. C. Pieper and collaborators work in both areas and have made the only calculations of 6- through 10-nucleon systems that use realistic interactions and that are accurate to 1–2% for the binding energies. The resulting wave functions can be used to compute properties measured at electron and hadron scattering facilities (in particular Jefferson Lab), and to compute astrophysical reaction rates, many of which cannot be measured in the laboratory.

	Figure 2   Proton and neutron densities for A = 10 nuclei on both linear (left) and logarithmic (right) scales.

Pieper et al. performed quantum Monte Carlo calculations of the ground and low-lying excited states of A = 9, 10 nuclei using realistic Hamiltonians containing a two-nucleon potential alone or with one of several three-nucleon potentials (Figure 2). They concluded that a fairly consistent picture of nuclear binding can be constructed for A < 10 nuclei using a single Hamiltonian and a single computational framework. This applies also to the energy differences among isobaric multiplets, which are well reproduced. Electromagnetic moments, within the limitation of the impulse approximation, are in fairly good agreement with experimental data.

INVESTIGATORS
S. C. Pieper, K. Varga, and R. B. Wiringa, Argonne National Laboratory.

PUBLICATION
S. C. Pieper, K. Varga, and R. B. Wiringa, “Quantum Monte Carlo calculations of A = 9, 10 nuclei,” Phys. Rev. C (submitted); preprint nucl-th/0206061 (2002).

URL
http://www.phy.anl.gov/theory/research/forces.html