相关论文: First-forbidden transitions and stellar $\beta$-de…
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…
In this work we studied $\beta$-decay properties for deformed neutron-rich nuclei in the region Z=36-43. We use the deformed pn-QRPA methods with the realistic CD-Bonn forces, and include both the Gamow-Teller and first-forbidden types of…
Superheavy nuclei represent the heaviest atoms and nuclides known at the limit of mass and charge. The observed superheavy nuclei are all proton-rich; they decay primarily by emitting $\alpha$ particles and fission, with a possible small…
We have performed large-scale shell-model calculations of the half-lives and neutron-branching probabilities of the r-process waiting point nuclei at the magic neutron numbers N=50, 82, and 126. The calculations include contributions from…
We study neutrinoless double-beta decay in an effective field theory (EFT) for heavy nuclei, which are treated as a spherical core coupled to additional neutrons and/or protons. Since the low-energy constants of the EFT cannot be fitted to…
$\beta$-decay half-lives of neutron-rich nuclei around $N=82$ are key data to understand the $r$-process nucleosynthesis. We performed large-scale shell-model calculations in this region using a newly constructed shell-model Hamiltonian,…
We propose a new method to calculate stellar weak-interaction rates. It is based on the Thermo-Field-Dynamics formalism and allows the calculation of the weak-interaction response of nuclei at finite temperatures. The thermal evolution of…
We study the recently measured beta-decay of $^{70}$Kr into $^{70}$Br within the framework of the large-scale shell model. The enhancement in the Gamow-Teller (GT) transition strength in $^{70}$Br compared to the $\beta$-decay of the…
During the presupernova evolution of massive stars, the isotopes of iron, $^{54,55,56}$Fe, are advocated to play a key role inside the cores primarily decreasing the electron-to-baryon ratio ($Y_{e}$) mainly via electron capture processes…
In the late progressive stages of heavy stars, electron capture and $\beta^\pm$-decay are the governing processes. The weak rates are essential inputs for modeling the stages of high-mass stars before supernova explosions. As per results…
We present the first \textit{ab initio} calculations of first-forbidden $\beta$ transitions which are important for understanding the reactor antineutrino anomaly. Starting from chiral two- plus three-nucleon forces, we derive both…
Electron capture on $^{20}$Ne is critically important for the final stage of evolution of stars with the initial masses of 8 - 10 $M_{\odot}$. In the present paper, we evaluate electron capture rates for a forbidden transition $^{20}$Ne…
In this paper, we reexamine one of the most promising candidates for determining the neutrino mass scale -- the unique first forbidden $\beta$ transition from $^{187}$Re($5/2^+$) to $^{187}$Os($1/2^-$). With the lowest-known ground-state to…
In this work, we have performed large-scale shell-model calculations for the first-forbidden $\beta ^{-}$ decay of $^{207}$Hg into the one-proton-hole nucleus $^{207}$Tl corresponding to the recently available experimental data from…
Employing the projected-Hartree-Fock-Bogoliubov (PHFB) model in conjunction with four different parametrizations of pairing plus multipolar effective two body interaction and three different parametrizations of Jastrow short range…
We propose a new model to calculate stellar electron capture rates for neutron-rich nuclei. These nuclei are encountered in the core-collapse of a massive star. Using the Shell Model Monte Carlo approach, we first calculate the finite…
We investigated the effects of first-forbidden transitions in $\beta$ decays on the production of the r-process $A \sim 195$ peak. The theoretical calculated $\beta$-decay rates with $\beta$-delayed neutron emission were examined using…
Gamow-Teller transitions in isotopes of chromium play a consequential role in the presupernova evolution of massive stars. $\beta$-decay and electron capture rates on chromium isotopes significantly affect the time rate of change of lepton…
In the present work, we report a systematic theoretical study of the $\log ft$ values for the forbidden $\beta^-$ decay transitions in the $^{208}$Pb region. For this, we have considered $^{206}$Hg $\rightarrow$ $^{206}$Tl, $^{208}$Hg…
The Gamow-Teller (GT) transition is inarguably one of the most important nuclear weak transitions of the spin-isosopin $\sigma\tau$ type. It has many applications in nuclear and astrophysics. These include, but are not limited to, r-process…