Microscopic calculations of {lambda} single-particle energies.

Conference · Thu Feb 12 04:00:00 EST 1998

OSTI ID:10634

Usmani, Q N

{Lambda} binding energy data for total baryon number A {le} 208 and for {Lambda} angular momenta {ell}{sub {Lambda}} {le} 3 are analyzed in terms of phenomenological (but generally consistent with meson-exchange) {Lambda}N and {Lambda}NN potentials. The Fermi-Hypernetted-Chain technique is used to calculate the expectation values for the {Lambda} binding to nuclear matter. Accurate effective {Lambda}N and {Lambda}NN potentials are obtained which are folded with the core nucleus nucleon densities to calculate the {Lambda} single particle potential U{sub {Lambda}}(r). We use a dispersive {Lambda}NN potential but also include an explicit {rho} dependence to allow for reduced repulsion in the surface, and the best fits have a large {rho} dependence giving consistency with the variational Monte Carlo calculations for {sub {Lambda}}{sup 5}He. The exchange fraction of the {Lambda}N space-exchange potential is found to be 0.2-0.3 corresponding to m{sub {Lambda}}* {approx_equal} (0.74-0.82)m{sub {Lambda}}. Charge symmetry breaking is found to be significant for heavy hypernuclei with a large neutron excess, with a strength consistent with that obtained from the A = 4 hypernuclei.

• Research Organization: Argonne National Lab., IL (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 10634
• Report Number(s): ANL/PHY/CP-95594
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANGULAR MOMENTUM
BARYON NUMBER
BINDING ENERGY
BOSON-EXCHANGE MODELS
EXPECTATION VALUE
HYPERNUCLEI
LAMBDA BARYONS
MONTE CARLO METHOD
SYMMETRY BREAKING