Elastic scattering of protons by /sup 16/O, /sup 40/Ca, and /sup 208/Pb at 200, 500, and 800 MeV: Relativistic and nonrelativistic analyses based on the impulse approximation

Journal Article · Mon Oct 31 23:00:00 EST 1988 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.38.2272· OSTI ID:7083227

Ottenstein, N; Wallace, S J; Tjon, J A

Systematics of Dirac impulse approximation predictions for cross sections and spin observables in elastic proton scattering by /sup 16/O, /sup 40/Ca, and /sup 208/Pb at energies of 200, 500, and 800 MeV are presented. The analysis is based on an optical potential constructed from complete sets of Lorentz-invariant NN amplitudes. The NN amplitudes are determined from a relativistic meson exchange model of the nuclear force. Comparisons are made with the original form of the Dirac impulse approximation, which is based on five Fermi terms to represent the NN interaction, and with the Schroedinger form of the impulse approximation. For the Dirac analyses, there is implicit coupling to virtual nucleon-antinucleon states. In order to illustrate these contributions, the Dirac equation is recast in the form of the Schroedinger equation and the resulting Schroedinger potentials are separated into ''no-pair'' and virtual-pair parts. The resulting virtual-pair part of the central potential is typically 25 MeV at the center of the nucleus for 200--800 MeV protons. A reasonable description of the experimental data is obtained over a broad energy range and over a wide variation of nuclear size when the analysis is based on complete sets of Lorentz-invariant amplitudes.

• Research Organization: Department of Physics and Astronomy, University of Maryland, College Park, Maryland 20742
• OSTI ID: 7083227
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 38:5; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

653001 -- Nuclear Theory-- Nuclear Structure
Moments
Spin
& Models
653003* -- Nuclear Theory-- Nuclear Reactions & Scattering
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AMPLITUDES
BARYON REACTIONS
BARYON-BARYON INTERACTIONS
BOSON-EXCHANGE MODELS
CALCIUM 40 TARGET
CHARGED-PARTICLE REACTIONS
DIFFERENTIAL EQUATIONS
DIRAC EQUATION
ELASTIC SCATTERING
ENERGY RANGE
EQUATIONS
FIELD THEORIES
GENERAL RELATIVITY THEORY
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
HELICITY
IMPULSE APPROXIMATION
INTERACTIONS
INVARIANCE PRINCIPLES
LEAD 208 TARGET
LORENTZ INVARIANCE
MATHEMATICAL MODELS
MEV RANGE
MEV RANGE 100-1000
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUCLEON-NUCLEON INTERACTIONS
OPTICAL MODELS
OXYGEN 16 TARGET
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PROPERTIES
PERIPHERAL MODELS
PROTON REACTIONS
RELATIVITY THEORY
SCATTERING
SCATTERING AMPLITUDES
SCHROEDINGER EQUATION
TARGETS
WAVE EQUATIONS