Calculation of {beta}decay rates in a relativistic model with momentumdependent selfenergies
Abstract
The relativistic protonneutron quasiparticle random phase approximation (PNRQRPA) is applied in the calculation of {beta}decay halflives of neutronrich nuclei in the Z{approx_equal}28 and Z{approx_equal}50 regions. The study is based on the relativistic HartreeBogoliubov calculation of nuclear ground states, using effective Lagrangians with densitydependent mesonnucleon couplings, and also extended by the inclusion of couplings between the isoscalar meson fields and the derivatives of the nucleon fields. This leads to a linear momentum dependence of the scalar and vector nucleon selfenergies. The residual QRPA interaction in the particlehole channel includes the {pi}+{rho} exchange plus a LandauMigdal term. The finiterange Gogny interaction is employed in the T=1 pairing channel, and the model also includes a protonneutron particleparticle interaction. The results are compared with available data, and it is shown that an extension of the standard relativistic meanfield framework to include momentumdependent nucleon selfenergies naturally leads to an enhancement of the effective (Landau) nucleon mass, and thus to an improved PNQRPA description of {beta}{sup }decay rates.
 Authors:
 Physics Department, Faculty of Science, University of Zagreb, Croatia, and PhysikDepartment der Technischen Universitaet Muenchen, D85748 Garching (Germany)
 (Germany)
 Publication Date:
 OSTI Identifier:
 20991005
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevC.75.024304; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; BETA DECAY; DENSITY; GROUND STATES; LAGRANGIAN FUNCTION; MEANFIELD THEORY; MESONS; NEUTRONRICH ISOTOPES; NEUTRONS; PARTICLE INTERACTIONS; PROTONS; RANDOM PHASE APPROXIMATION; RELATIVISTIC RANGE; SELFENERGY
Citation Formats
Marketin, T., Vretenar, D., Ring, P., and PhysikDepartment der Technischen Universitaet Muenchen, D85748 Garching. Calculation of {beta}decay rates in a relativistic model with momentumdependent selfenergies. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVC.75.024304.
Marketin, T., Vretenar, D., Ring, P., & PhysikDepartment der Technischen Universitaet Muenchen, D85748 Garching. Calculation of {beta}decay rates in a relativistic model with momentumdependent selfenergies. United States. doi:10.1103/PHYSREVC.75.024304.
Marketin, T., Vretenar, D., Ring, P., and PhysikDepartment der Technischen Universitaet Muenchen, D85748 Garching. Thu .
"Calculation of {beta}decay rates in a relativistic model with momentumdependent selfenergies". United States.
doi:10.1103/PHYSREVC.75.024304.
@article{osti_20991005,
title = {Calculation of {beta}decay rates in a relativistic model with momentumdependent selfenergies},
author = {Marketin, T. and Vretenar, D. and Ring, P. and PhysikDepartment der Technischen Universitaet Muenchen, D85748 Garching},
abstractNote = {The relativistic protonneutron quasiparticle random phase approximation (PNRQRPA) is applied in the calculation of {beta}decay halflives of neutronrich nuclei in the Z{approx_equal}28 and Z{approx_equal}50 regions. The study is based on the relativistic HartreeBogoliubov calculation of nuclear ground states, using effective Lagrangians with densitydependent mesonnucleon couplings, and also extended by the inclusion of couplings between the isoscalar meson fields and the derivatives of the nucleon fields. This leads to a linear momentum dependence of the scalar and vector nucleon selfenergies. The residual QRPA interaction in the particlehole channel includes the {pi}+{rho} exchange plus a LandauMigdal term. The finiterange Gogny interaction is employed in the T=1 pairing channel, and the model also includes a protonneutron particleparticle interaction. The results are compared with available data, and it is shown that an extension of the standard relativistic meanfield framework to include momentumdependent nucleon selfenergies naturally leads to an enhancement of the effective (Landau) nucleon mass, and thus to an improved PNQRPA description of {beta}{sup }decay rates.},
doi = {10.1103/PHYSREVC.75.024304},
journal = {Physical Review. C, Nuclear Physics},
number = 2,
volume = 75,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}

The Lagrangian density of standard relativistic meanfield models with densitydependent mesonnucleon coupling vertices is modified by introducing couplings of the meson fields to derivative nucleon densities. As a consequence, the nucleon selfenergies that describe the effective inmedium interaction become momentum dependent. In this approach it is possible to increase the effective (Landau) mass of the nucleons, that is related to the density of states at the Fermi energy, as compared to conventional relativistic models. At the same time the relativistic effective (Dirac) mass is kept small to obtain a realistic strength of the spinorbit interaction. Additionally, the empirical Schroedingerequivalent centralmore »

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