Studies of the nucleon-nucleus first-order optical potential

Thesis/Dissertation · Sat Jan 01 00:00:00 EST 1983

OSTI ID:5966331

Wolfe, D H

Microscopic first-order optical potential calculations of intermediate energy proton-nucleus elastic scattering are made using the Kerman, McManus, and Thaler multiple-scattering theory. Comparisons are made between various on-shell (local) prescriptions for the factorization of the folding integral, with both local and nonlocal off-shell prescriptions. All calculations are purely microscopic, parameter free, and performed entirely with the momentum-space representation. In particular, the Lippmann-Schwinger integral equation is solved using relativistic kinematics. A computer code, WIZARD 1, is developed to handle all aspects of the calculations. The first-order optical potential calculations employ the realistic free nuclon-nucleon t-matrix models of Love-Franey and Picklesimer-Walker, along with reasonable representations for the nuclear densities based on either three-parameter Fermi shapes or shell-model constructions. This work represents the first systematic study of the influence of non-local and off-shell effects in the first-order theory of the optical potential for protons over a range of energies and targets. Results indicate that the usual on-shell (local) factorization of the t-matrix is not an adequate treatment of the folding integral at momentum transfers beyond that which corresponds to the maximum physical nucleon-nucleon value. This result implies the need for a model of the reaction mechanism which prescribes how the off-shell momenta and energy of the t-matrix are to be folded with the nuclear density matrix. It is concluded that the full folding calculation of the Fermi averaging integral is necessary, particularly at lower energies, to fully calibrate the use of first-order theory for the optical potential.

• Research Organization: Kent State Univ., OH (USA)
• OSTI ID: 5966331
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
PROTON REACTIONS
ELASTIC SCATTERING
OPTICAL MODELS
LIPPMANN-SCHWINGER EQUATION
NUCLEAR POTENTIAL
NUCLEI
BARYON REACTIONS
CHARGED-PARTICLE REACTIONS
EQUATIONS
HADRON REACTIONS
INTEGRAL EQUATIONS
NUCLEAR REACTIONS
NUCLEON REACTIONS
POTENTIALS
SCATTERING
653003* - Nuclear Theory- Nuclear Reactions & Scattering