Uniform semiclassical and quantum calculations of Regge pole positions and residues for complex optical nuclear heavy-ion potentials

Journal Article · Mon Nov 01 00:00:00 EST 1993 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.48.2419· OSTI ID:5918316

Connor, J N.L. ^[1]; Farrelly, D ^[2]

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1. Department of Chemistry, University of Manchester, Manchester M13 9PL (United Kingdom)
2. Department of Chemistry, University of Manchester, Manchester M13 9PL (United Kingdom) Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322 (United States)

The first uniform semiclassical (SC) calculations of Regge pole positions and residues have been carried out for four complex optical potentials, which have been used to fit [sup 16]O+[sup 28]Si elastic-scattering data at [ital E][sub lab]=55 MeV. In particular, we have extended a SC formalism developed for atomic and molecular scatterings to allow for the presence of a long-range Coulomb potential. The SC Regge poles and residues are compared with quantum results of Takemasa and Tamura [Phys. Rev. C 18, 1282 (1978)], who numerically integrated the radial Schroedinger equation. The SC computations show that Takemasa and Tamura missed ten poles. Using a modified version of the quantum computer code REGGE, due to Takemasa, Tamura, and Wolter [Comput. Phys. Commun. 18, 427 (1979)] we have located five of these poles---the remaining poles have residues of modulus [lt]10[sup [minus]8]. For low values of the Regge pole quantum number, [ital n], the SC and quantum pole positions are in close agreement, with larger differences for the residues. As [ital n] increases, the SC results become less accurate. However at high values of [ital n], the quantum results also lose accuracy due to numerical instabilities in the REGGE code. It is demonstrated that the choice of Coulomb interaction---charged sphere or pure Coulomb---can significantly effect the properties of the Regge pole positions and residues.

• OSTI ID: 5918316
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Vol. 48:5; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
HEAVY ION REACTIONS
OPTICAL MODELS
REGGE POLES
SEMICLASSICAL APPROXIMATION
COMPUTER CODES
DATA ANALYSIS
ELASTIC SCATTERING
OXYGEN 16 REACTIONS
SILICON 28 TARGET
CHARGED-PARTICLE REACTIONS
NUCLEAR REACTIONS
SCATTERING
TARGETS
662240* - Models for Strong Interactions- (1992-)
663300 - Nuclear Reactions & Scattering
General- (1992-)
663450 - Heavy-Ion-Induced Reactions & Scattering- (1992-)
663530 - Nuclear Mass Ranges- A=20-38- (1992-)