Two-body weak currents in heavy nuclei

Abstract

In light and medium-mass nuclei, two-body weak currents from chiral effective field theory account for a significant portion of the phenomenological quenching of Gamow-Teller transition matrix elements. Here we examine the systematic effects of two-body axial currents on Gamow-Teller strength and $\beta$-decay rates in heavy nuclei within energy-density functional theory. Using a Skyrme functional and the charge-changing finite amplitude method, we add the contributions of two-body currents to the usual one-body linear response in the Gamow-Teller channel, both exactly and though a density-matrix expansion. The two-body currents, as expected, usually quench both summed Gamow-Teller strength and decay rates, but by an amount that decreases as the neutron excess grows. In addition, they can enhance individual low-lying transitions, leading to decay rates that are quite different from those that an energy-independent quenching would produce, particularly in neutron-rich nuclei. We show that both these unexpected effects are related to changes in the total nucleon density as the number of neutrons increases.

arXiv comment13 pages, 8 figures

References in corpus (38)

• Accurate Charge-Dependent Nucleon-Nucleon Potential at Fourth Order of Chiral Perturbation Theory
• The two-nucleon system at next-to-next-to-next-to-leading order
• Status and Future of Nuclear Matrix Elements for Neutrinoless Double-Beta Decay: A Review
• Discrepancy between experimental and theoretical $\beta$-decay rates resolved from first principles
• Large scale evaluation of beta-decay rates of r-process nuclei with the inclusion of first-forbidden transitions
• The effective g_A in the pf-shell
• Axially Deformed Solution of the Skyrme-Hartree-Fock-Bogolyubov Equations using The Transformed Harmonic Oscillator Basis. The program HFBTHO (v1.66p)
• Axially deformed solution of the Skyrme-Hartree-Fock-Bogolyubov equations using the transformed harmonic oscillator basis (II) HFBTHO v2.00d: a new version of the program
• Chiral two-body currents in nuclei: Gamow-Teller transitions and neutrinoless double-beta decay
• Local Density Approximation for proton-neutron pairing correlations. I. Formalism
• Value of the axial-vector coupling strength in $\beta$ and $\beta \beta$ decays: A review
• Large-scale nuclear structure calculations for spin-dependent WIMP scattering with chiral effective field theory currents
• Parameter-free effective field theory calculation for the solar proton-fusion and hep processes
• Finite amplitude method for the RPA solution
• Spin-dependent WIMP scattering off nuclei
• Determination of the chiral coupling constants c3 and c4 in new pp and np partial-wave analyses
• Particle-vibration coupling within covariant density functional theory
• Finite amplitude method for the quasi-particle-random-phase approximation
• Solution of the Skyrme-Hartree-Fock-Bogolyubov equations in the Cartesian deformed harmonic-oscillator basis. (VI) HFODD (v2.38j): a new version of the program
• Global description of beta-minus decay in even-even nuclei with the axially-deformed Skyrme finite amplitude method
• Global Description of Beta Decay with the Axially-Deformed Skyrme Finite Amplitude Method: Extension to Odd-Mass and Odd-Odd Nuclei
• Nuclear axial current operators to fourth order in chiral effective field theory
• Tensor hypercontraction: A universal technique for the resolution of matrix elements of local, finite-range $N$-body potentials in many-body quantum problems
• Quantum Monte Carlo calculations of weak transitions in $A$=6--10 nuclei
• Axially deformed solution of the Skyrme-Hartree-Fock-Bogolyubov equations using the transformed harmonic oscillator basis (III) hfbtho (v3.00): a new version of the program
• Chiral Effective Field Theory Calculations of Weak Transitions in Light Nuclei
• Nuclear Axial Currents in Chiral Effective Field Theory
• Finite Amplitude Method for Charge-Changing Transitions in Axially-Deformed Nuclei
• Low energy collective modes of deformed superfluid nuclei within the finite amplitude method
• An improved density matrix expansion for spin-unsaturated nuclei
• Beta decay of deformed r-process nuclei near A = 80 and A= 160, including odd-A and odd-odd nuclei, with the Skyrme finite-amplitude method
• Quenching of nuclear matrix elements for $0\nu \beta \beta$ decay by chiral two-body currents
• Testing the density matrix expansion against ab initio calculations of trapped neutron drops
• Microscopically-based energy density functionals for nuclei using the density matrix expansion: Full optimization and validation
• The Negele-Vautherin density matrix expansion applied to the Gogny force
• Gaussian matrix elements in a cylindrical harmonic oscillator basis
• Applying the Density Matrix Expansion with Coordinate-Space Chiral Interactions
• Microscopically based energy density functionals for nuclei using the density matrix expansion

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