Relativity and the enhancement of the weak axial-charge matrix elements in the lead region

Journal Article · Sat Aug 01 00:00:00 EDT 1992 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.46.788· OSTI ID:7035248

Gattone, A O; Izquierdo, E D; Chiapparini, M ^[1]

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1. TANDAR-Comision Nacional de Energia Atomica, Avenida del Libertador 8250, 1429 Buenos Aires (Argentina)

We present a calculation of first-forbidden {beta}-decay transitions in the lead region using relativistic mean-field and relativistic Hartree approximations to a quantum hydrodynamic model of Serot and Walecka. A formalism for the response of the core to a valence particle or hole in the case of weak transitions is developed and studied for the {pi}- and {rho}-meson fields present in the model. Two applications are shown for which the mean-field results show a sizable enhancement of the matrix element. This enhancement is partly quenched by the inclusion of the vacuum corrections. The core response for these cases turns out to be negligible in the long wavelength limit. Altogether, it is concluded that the relativistic effects discriminate against nonrelativistic calculations but, however, are not enough to account for the recently reported discrepancy between shell model analysis of beta-decay rates and the (nonrelativistic) impulse approximation and meson-exchange-current calculations.

• OSTI ID: 7035248
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Journal Name: Physical Review, C (Nuclear Physics); (United States) Vol. 46:2; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

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663580 -- Nuclear Mass Ranges-- A=190-219-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALGEBRAIC CURRENTS
AXIAL-VECTOR CURRENTS
BASIC INTERACTIONS
BETA DECAY
BOSON-EXCHANGE MODELS
CURRENTS
DECAY
DIFFERENTIAL EQUATIONS
DIRAC EQUATION
ENERGY-LEVEL TRANSITIONS
EQUATIONS
FORBIDDEN TRANSITIONS
HARTREE-FOCK METHOD
INTERACTIONS
ISOTOPES
LEAD ISOTOPES
MATHEMATICAL MODELS
MATRIX ELEMENTS
MEAN-FIELD THEORY
NUCLEAR DECAY
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE MODELS
PERIPHERAL MODELS
WAVE EQUATIONS
WEAK INTERACTIONS