Meson-exchange-current corrections to magnetic moments in quantum hadrodynamics

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1990

OSTI ID:7205972

Morse, T M

Corrections to the magnetic moments of the non-relativistic shell model (Schmidt lines) have a long history. In the early fifties calculations of pion exchange and core polarization contributions to nuclear magnetic moments were initiated. These calculations matured by the early eighties to include other mesons and the delta isobar. Relativistic nuclear shell model calculations are relatively recent. Meson exchange and the delta isobar current contributions to the magnetic moments of the relativistic shell model have remained largely unexplored. The disagreement between the valence values of spherical relativistic mean-field models and experiment was a major problem with early (1975-1985) quantum hydrodynamics (QHD) calculations of magnetic moments. Core polarization calculations (1986-1988) have been found to resolve the large discrepancy, predicting isoscalar magnetic moments to within typically five percent of experiment. The isovector magnetic moments, however, are about twice as far from experiment with an average discrepancy of about ten percent. The pion, being the lightest of the mesons, has historically been expected to dominate isovector corrections. Because this has been found to be true in non-relativistic calculations, the author calculated the pion corrections in the framework of QHD. The seagull and in-flight pion exchange current diagram corrections to the magnetic moments of eight finite nuclei (plus or minus one valence nucleon from the magic A = 16 and A = 40 doubly closed shell systems) are calculated in the framework of QHD, and compared with earlier non-relativistic calculations and experiment.

• Research Organization: Colorado Univ., Boulder, CO (United States)
• OSTI ID: 7205972
• Country of Publication: United States
• Language: English

Related Subjects

663120* -- Nuclear Structure Models & Methods-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BOSON-EXCHANGE MODELS
COMPARATIVE EVALUATIONS
CORRECTIONS
ELEMENTARY PARTICLES
EVALUATION
FIELD THEORIES
GENERAL RELATIVITY THEORY
HADRONS
ISOVECTORS
MAGIC NUCLEI
MAGNETIC MOMENTS
MATHEMATICAL MODELS
MEAN-FIELD THEORY
NUCLEAR MAGNETIC MOMENTS
NUCLEAR MODELS
NUCLEAR PROPERTIES
NUCLEI
OBE MODEL
OPE MODEL
PARTICLE MODELS
PERIPHERAL MODELS
RELATIVITY THEORY
SHELL MODELS
TENSORS
VECTORS