Elastic scattering of protons by /sup 16/O, /sup 40/Ca and /sup 208/Pb at 200, 500 and 800 MeV: 1, Relativistic and nonrelativistic analyses based on the impulse approximation

Technical Report · Sat Oct 31 23:00:00 EST 1987

OSTI ID:5603310

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 MeV to 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. 34 refs., 23 figs.

• Research Organization: Maryland Univ., College Park (USA). Dept. of Physics and Astronomy; Rijksuniversiteit Utrecht (Netherlands). Inst. voor Theoretische Fysica
• DOE Contract Number: FG05-87ER40322
• OSTI ID: 5603310
• Report Number(s): DOE/ER/40322-010; ON: DE88005764
• Country of Publication: United States
• Language: English

Related Subjects

653003* -- Nuclear Theory-- Nuclear Reactions & Scattering
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYON REACTIONS
BARYON-BARYON INTERACTIONS
CALCIUM 40 TARGET
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DATA
DIFFERENTIAL CROSS SECTIONS
ELASTIC SCATTERING
ENERGY RANGE
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
IMPULSE APPROXIMATION
INFORMATION
INTERACTIONS
INVARIANCE PRINCIPLES
LEAD 208 TARGET
LORENTZ INVARIANCE
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUCLEON-NUCLEON INTERACTIONS
NUMERICAL DATA
OXYGEN 16 TARGET
PARTICLE INTERACTIONS
PROTON REACTIONS
RELATIVISTIC RANGE
SCATTERING
TARGETS
THEORETICAL DATA