Weak Magnetism in Two Neutrino Double Beta Decay

Abstract

We have extended the formalism for the two-neutrino double beta decay by including the weak-magnetism term, as well as other second-forbidden corrections. The weak magnetism diminishes the calculated half-lives in $\sim 10$, independently of the nuclear structure. Numerical computations were performed within the pn-QRPA, for ${}^{76}Ge$, ${}^{82}Se$, ${}^{100}Mo$, ${}^{128}Te$ and ${}^{130}Te$ nuclei. No one of the second-forbidden corrections modifies significantly the spectrum shapes. The total reduction in the calculated half lives varies from 6% up to 32%, and strongly depend on the nuclear interaction in the particle-particle $S=1,T=0$ channel. We conclude that the higher order effects in the weak Hamiltonian would hardly be observed in the two-neutrino double beta experiments.

8 pages, latex, 1ps figure, to appear in Phys. Lett. B

References in corpus (2)

• Nuclear moments for the neutrinoless double beta decay
• Competition between standard and exotic double beta decays

Cited by in corpus (4)

• Additional Nucleon Current Contributions to Neutrinoless Double Beta Decay
• Limits on different Majoron decay modes of ${}^{100}$Mo and ${}^{82}$Se for neutrinoless double beta decays in the NEMO-3 experiment
• First Search for Lorentz and CPT Violation in Double Beta Decay with EXO-200
• Partial restoration of spin-isospin SU(4) Symmetry and the One-QRPA method in Double Beta Decay