Interplay of resonant and l-window background amplitudes in /sup 16/O+/sup 16/O

Journal Article · Mon Apr 01 04:00:00 EST 1985 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.31.1255· OSTI ID:5817730

Gai, M; Korotky, S K; Manoyan, J M; Schloemer, E C; Shivakumar, B; Sterbenz, S M; Willett, S J; Bromley, D A; Voit, H

High resolution study of the /sup 16/O+/sup 16/O system at 15.5 < or =E/sub c.m./< or =17.0 MeV is reported including excitation functions for elastic scattering, and angle integrated cross sections for ..cap alpha../sub 0/ and ..cap alpha../sub 1/ exit channels and several ..gamma..-ray channels. All show correlated resonant structure. Fifteen angular distributions for the ..cap alpha../sub 0/ and ..cap alpha../sub 1/ exit channels are measured in ..delta..E/sub c.m./approx. =50 keV steps for 15.5< or =E/sub c.m./< or =16.4 MeV in the angular range 17/sup 0/< or =theta/sub c.m./< or =93/sup 0/ in steps of ..delta..theta/sub c.m./approx. =2.5/sup 0/. Phase shift analysis of the ..cap alpha../sub 0/ angular distribution was carried out. Ambiguities in the extraction of the S matrix elements are removed using the usual techniques with an additional new constraint: the measurement of cross section at selected angles (zeros of P/sub l/) arising from a single partial wave. Reaction amplitudes corresponding to a narrow l window around the grazing partial wave are shown to dominate the cross section around theta/sub c.m./ = 90/sup 0/. The grazing partial wave shows broad nonresonant structure; a specific parametrization of the energy dependence of the nonresonant (background) cross section corresponding to the l window is presented. The interplay of background amplitudes (l window) and resonant amplitudes is emphasized. Resonances in the ..cap alpha../sub 0/ channel are located at E/sub c.m./ = 15.8, 15.9, and 16.1 MeV having J/sup ..pi../ = 10/sup +/, 8/sup +/, and 8/sup +/, respectively, and intermediate widths (GAMMAapprox.70 keV).

• Research Organization: A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06511
• DOE Contract Number: AC02-76ER03074
• OSTI ID: 5817730
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 31:4; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651325* -- Nuclear Properties &amp; Reactions
A=6-19
Experimental-- Nuclear Reactions &amp; Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
ANGULAR MOMENTUM
CHARGED-PARTICLE REACTIONS
COULOMB FIELD
CROSS SECTIONS
DISTRIBUTION
ELASTIC SCATTERING
ELECTRIC FIELDS
ELECTROMAGNETIC RADIATION
ENERGY DEPENDENCE
ENERGY RANGE
EXCITATION FUNCTIONS
FUNCTIONS
GAMMA RADIATION
HEAVY ION REACTIONS
INELASTIC SCATTERING
IONIZING RADIATIONS
LEGENDRE POLYNOMIALS
MATRICES
MATRIX ELEMENTS
MEV RANGE
MEV RANGE 10-100
NUCLEAR REACTIONS
OXYGEN 16 REACTIONS
OXYGEN 16 TARGET
PARITY
PARTICLE PROPERTIES
PHASE SHIFT
POLYNOMIALS
RADIATIONS
RESONANCE SCATTERING
S MATRIX
SCATTERING
SPIN
TARGETS