Isospin dependence of second-order pion-nucleus optical potential

Journal Article · Tue Feb 01 04:00:00 EST 1983 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.27.730· OSTI ID:6235156

Johnson, M B; Siciliano, E R

A universal form for the dependence of the second-order pion-nuclear optical potential on the nuclear and pionic isospin and on the densities rho and ..delta..rho is derived, where rho is the total density and ..delta..rho is the valence neutron density. The result is characterized by five complex parameters for each partial wave channel contributing to the optical potential. Our result applies to scattering in the vicinity of the (3,3) resonance, and the parameters may be most cleanly determined phenomenologically by applying the theory to elastic, and single- and double-charge-exchange data for medium to heavy weight J = 0, spherical nuclei. The relationship between the parameters and a microscopic cluster decomposition of the optical potential is explored. The parameters are calculated theoretically for selected second-order processes to obtian a first orientation to the magnitude of the terms. The results show, in particular, that large contributions to double charge exchange arise from nonanalog intermediate nuclear states and that these contributions have a characteristic isospin dependence which is different from that found in the simple models previously studied.

• Research Organization: Los Alamos National Laboratory, Los Alamos, New Mexico 87545
• OSTI ID: 6235156
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 27:2; 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
CHARGE-EXCHANGE REACTIONS
CHARGED-PARTICLE REACTIONS
ELASTIC SCATTERING
ENERGY LEVELS
HADRON REACTIONS
ISOBARIC ANALOGS
ISOSPIN
MESON REACTIONS
NUCLEAR REACTIONS
OPTICAL MODELS
PARTICLE PROPERTIES
PION REACTIONS
SCATTERING