Pion double charge exchange in the. Delta. sub 33 resonance region

Journal Article · Fri Dec 01 04:00:00 EST 1989 · Physical Review (Section) C: Nuclear Physics; (USA)

DOI:https://doi.org/10.1103/PhysRevC.40.2745· OSTI ID:7016804

Wirzba, A ^[1]; Toki, H ^[2]; Siciliano, E R; Johnson, M B ^[3]; Gilman, R ^[4]

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1. Nordisk Institut for Teoretisk Atomfysik, Blegdamsvej 17, DK-2100 Copenhagen, (Denmark)
2. Tokyo Metropolitan University, Tokyo 158, (Japan)
3. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA)
4. University of Pennsylvania, Philadelphia, Pennsylvania 19104 (USA)

We examine the model dependence and nuclear-structure sensitivity of several {Delta}{sub 33}-dominated processes contributing to pion double charge exchange on nuclei in the region of the {Delta}{sub 33} resonance. These processes include the {Delta}{sub 33}-nucleon interaction {ital V}{sub {ital N}{Delta}} and sequential scattering, in which the pion undergoes single charge exchange on two different nucleons. In all cases, the scattering takes place through the exchange of an intermediate {pi} and {rho} meson. Sequential-mediated double charge exchange is found to be only moderately sensitive to short-range correlations, meson-nucleon form factors, and the rho meson, whereas {ital V}{sub {ital N}{Delta}}-mediated double charge exchange is very sensitive to all these effects. Results are given for double charge exchange on {sup 18}O (double isobaric analog transitions) and {sup 16}O (nonanalog transitions). Sequential double charge exchange is shown to favor non-spin-flip matrix elements of the transition operator whereas {ital V}{sub {ital N}{Delta}}-mediated double charge exchange favors spin-flip matrix elements. The energy dependence of the zero-degree cross sections for {ital V}{sub {ital N}{Delta}} and sequential scattering are also different: Sequential tends to increase monotonically from 100 to 300 MeV, whereas {ital V}{sub {ital N}{Delta}} peaks at about 150 MeV. The delta-nucleon interaction is found likely to dominate over sequential scattering in nonanalog double charge exchange. The {ital V}{sub {ital N}{Delta}} is also large in analog double charge exchange, but it does not enable us to explain the anomalous behavior of the {sup 18}O differential cross sections.

• OSTI ID: 7016804
• Journal Information: Physical Review (Section) C: Nuclear Physics; (USA), Journal Name: Physical Review (Section) C: Nuclear Physics; (USA) Vol. 40:6; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

653003* -- Nuclear Theory-- Nuclear Reactions & Scattering
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR MOMENTUM
BARYONS
BOSON-EXCHANGE MODELS
BOSONS
CHARGE EXCHANGE
CHARGED-PARTICLE REACTIONS
COMPOSITE MODELS
COUPLING CONSTANTS
DELTA BARYONS
DELTA-1232 BARYONS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
FORM FACTORS
HADRON REACTIONS
HADRONS
LIE GROUPS
MATHEMATICAL MODELS
MATRIX ELEMENTS
MESON REACTIONS
MESONS
MEV RANGE
MEV RANGE 100-1000
N BARYONS
NUCLEAR REACTIONS
NUCLEAR STRUCTURE
NUCLEONS
OBE MODEL
OPE MODEL
OXYGEN 16 TARGET
OXYGEN 18 TARGET
PARTICLE MODELS
PARTICLE PROPERTIES
PERIPHERAL MODELS
PION REACTIONS
QUARK MODEL
RHO-770 MESONS
SPIN
SU GROUPS
SU-2 GROUPS
SYMMETRY GROUPS
TARGETS
VECTOR MESONS