Effective interaction for sup 16 O( p , p prime ) at E sub p =318 MeV

Journal Article · Thu Feb 28 23:00:00 EST 1991 · Physical Review, C (Nuclear Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevC.43.1272· OSTI ID:6200940

Kelly, J J; Feldman, A E; Flanders, B S; Seifert, H ^[1]; Lopiano, D; Aas, B; Azizi, A; Igo, G; Weston, G; Whitten, C; Wong, A ^[2]; Hynes, M V; McClelland, J ^[3]; Bertozzi, W; Finn, J M; Hyde-Wright, C E; Lourie, R W; Ulmer, P E ^[4]; Norum, B E ^[5]; Berman, B L ^[6]

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1. Department of Physics and Astronomy, University of Maryland, College Park, Maryland 20742 (USA)
2. Department of Physics, University of California at Los Angeles, Los Angeles, California (USA)
3. Los Alamos National Laboratory, Los Alamos, New Mexico (USA)
4. Massachusetts Institute of Technology, Cambridge, Massachusetts (USA). Department of Physics Massachusetts Institute of Technology, Cambridge, Massachusetts (USA). Laboratory for Nuclear Science
5. Department of Physics, University of Virginia, Charlottesville, Virginia (USA)
6. Department of Physics, George Washington University, Washington, D.C. (USA)

We report new cross-section and analyzing power data for the excitation by 318 MeV protons of 20 states of {sup 16}O below 14 MeV. The data for normal-parity isoscalar excitations are compared with calculations based upon the nonrelativistic impulse approximation using both density-independent and density-dependent interactions in the local-density approximation. These comparisons clearly indicate that density-dependent modifications of the effective interaction are required. Although the Paris-Hamburg, Nakayama-Love, and Ray interactions all predict significant medium modifications, none describes the data particularly well. Therefore, we fitted an empirical effective interaction to the data for five inelastic transitions simultaneously using a self-consistency cycle that maintains consistency between transition potentials and microscopic distorting potentials. This interaction describes the inelastic data as well as elastic data and data for {sup 40}Ca which were not included in the fitting procedure. Therefore, the local-density approximation is supported by the phenomenology. However, medium modifications of the effective interaction are substantially stronger than predicted and persist to low density. The optical potentials are similar to the Schroedinger-equivalent potentials from the relativistic IA2 model, showing that the equivalent density dependence due to virtual {ital N{bar N}} pairs is comparable to the short-range repulsion fitted to inelastic-scattering data.

• OSTI ID: 6200940
• Journal Information: Physical Review, C (Nuclear Physics); (USA), Journal Name: Physical Review, C (Nuclear Physics); (USA) Vol. 43:3; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651320* -- Nuclear Properties & Reactions
A=6-19
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANALYZING POWER
BARYON REACTIONS
BEAMS
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
ELASTIC SCATTERING
ENERGY RANGE
HADRON REACTIONS
IMPULSE APPROXIMATION
INELASTIC SCATTERING
MEV RANGE
MEV RANGE 100-1000
NUCLEAR REACTIONS
NUCLEON REACTIONS
OXYGEN 16 TARGET
POLARIZED BEAMS
PROTON REACTIONS
SCATTERING
TARGETS