Related papers: Two-phonon structures for beta-decay theory
[Background] $\beta$-decay half-life is sensitive to the shell structure near the Fermi levels. Nuclear deformation thus impacts the $\beta$-decay properties. [Purpose] A first-order shape-phase transition in neutron-rich Zr isotopes is…
Background: Two-phonon excitations originating from the coupling of two collective one-phonon states are of great interest in nuclear structure physics. One possibility to generate low-lying $E1$ excitations is the coupling of quadrupole…
In the present paper we treat the second-forbidden non-unique (2nd-nu) ground-state-to-ground-state $\beta^-$ decay $^{99}\textrm{Tc}(9/2^+)\to\,^{99}\textrm{Ru}(5/2^+)$, with a 100$\%$ branching ratio, within the framework of the nuclear…
The Gamow-Teller strength distribution of the decay of $^{186}$Hg into $^{186}$Au has been determined for the first time using the total absorption gamma spectroscopy technique and has been compared with theoretical QRPA calculations using…
I studied the distribution of ranks of values of 2949 {\beta}-decay half-lives according to an empirical beta law with two exponents. {\beta}-decay half-life ranks showed good fit to a beta function with two exponents.
In this paper, beta-decay properties of even-even neutron-rich isotopes in the rare-earth mass region are studied within a microscopic theoretical approach based on a proton-neutron quasiparticle random-phase approximation. The underlying…
Using an angular momentum projected single particle basis, a pnQRPA approach is used to study the $2\nu\beta\beta$ properties of ten isotopes, exhibiting various quadrupole deformations. The mother and daughter nuclei exhibit different…
The effect of nuclear deformation on the energy distributions of the Gamow-Teller strength is studied in neutron-deficient Hg, Pb, and Po even isotopes. The theoretical framework is based on a self-consistent deformed Skyrme Hartree-Fock…
We report on high-statistics data from the $\beta^-$ decay of the $^{46}$K $J^{\pi}$ = 2$^-$ ground state taken with the GRIFFIN spectrometer located at the TRIUMF-ISAC facility. In total, 199 $\gamma$ rays and 42 excited states were placed…
Beta-decay rates of extreme neutron-rich nuclei remain largely unknown experimentally, while they are critical inputs for $r$-process nucleosynthesis. We present first ab initio calculations of total beta-decay half-lives, with a focus on…
We have measured the angular distribution of recoiling daughter nuclei emitted from the Gamow-Teller $\beta$ decay of spin-polarized $^{80}$Rb. The asymmetry of this distribution vanishes to lowest order in the Standard Model (SM) in pure…
After briefly reviewing $\beta \beta$ decay as a test of the neutrino mass, I examine the nuclear structure involved in this process. Simple formulas (\`{a} la Pad\'{e}) are designed for the transition amplitudes and the general behavior of…
Nuclear double $\beta$-decay with two neutrinos is a rare and important process for natural radioactivity of unstable nuclei. The experimental data of nuclear double $\beta^{-}$-decay with two neutrinos are analyzed and a systematic law to…
We study two-neutrino ($2\nu\beta\beta$) and neutrinoless double-$\beta$ ($0\nu\beta\beta$) decays in the nuclear shell model and proton-neutron quasiparticle random-phase approximation (pnQRPA) frameworks. Calculating the decay half-life…
Half-lives $T_{1/2}^{2\nu}$ for two neutrino positron double beta decay modes $\beta^{+}$EC/ECEC are calculated for $^{74}$Se, a nucleus of current experimental interest, using deformed shell model based on Hartree-Fock states employing a…
We studied the temperature effect in isospin-singlet pairings in Gamow-Teller excitations. We use theories of a hole-particle in the mean field shell model studied decay transition using the one-particle-one-hole model for the $\beta$-decay…
Half-lives $T_{1/2}^{2\nu}$ for two neutrino positron double beta decay modes $\beta^{+}$EC/ECEC are calculated for $^{84}$Sr, a nucleus of current experimental interest, within the framework of the deformed shell model based on…
The lifetimes for the double beta decays of $^{76}$Ge, $^{82}$Se and $^{136}$Xe are calculated using very large shell model spaces. The two neutrino matrix elements obtained are in good agreement with the present experimental data. For…
The double beta decay of 100Mo to the 0^+_1 and 2^+_1 excited states of 100Ru is studied using the NEMO 3 data. After the analysis of 8024 h of data the half-life for the two-neutrino double beta decay of 100Mo to the excited 0^+_1 state is…
Neutrinoless double-beta decay represents the most promising approach for revealing some of the most important, yet-unknown, properties of neutrinos related to their absolute masses and their nature. This transition involves beyond standard…