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A systematic study on the alpha decay half-lives of various isotopes of superheavy element (SHE) within the range is presented for the first time using Coulomb and proximity potential model for deformed nuclei (CPPMDN). The calculated decay half-lives of the isotopes within our formalism match well with the values computed using Viola-Seaborg systematic, Universal curve of Poenaru et al., and the analytical formula of Royer. In our study by comparing the decay half-lives with the spontaneous fission half-lives, we have predicted chain from 121, chain from 121 and chain from 121. Clearly our study shows that the isotopes of SHE within the mass range will survive fission and can be synthesized and detected in the laboratory via alpha decay. We hope that our predictions will provide a new guide to future experiments. [ABSTRACT FROM AUTHOR]

The half-lives of even-even nuclei with proton number Z ≥ 94 are calculated by proximity potential with a new universal function, especially for superheavy nuclei. The calculation results are compared to the experimental data. It is shown that from the presently obtained universal function, the calculated half-lives of α decay can basically keep agreement with the experimental data for most of even-even nuclei. Those of superheavy nuclei are also calculated and discussed. [ABSTRACT FROM AUTHOR]

In this paper, Coulomb and proximity potential model has been applied to calculate the half-lives of alpha-decay for isotopes around N = Z = 50. Using this model, we investigated the influence of deformation and orientation of daughter nucleus on alpha-decay half-lives. Two orientations (90° and 180°) with quadrupole deformation are applied to study the role of daughter orientation in alpha-decay process. It is found that the deformation and orientation of daughter nucleus affects the alpha-decay half-life and changes the slope and intercept of linear relation between log10(T1/2) and Q-1/2. [ABSTRACT FROM AUTHOR]

In this paper, the half-life values of spherical proton emitters such as , , , , , , , and have been calculated within the framework of fractional calculus. Nuclear decay equation, related to this phenomenon, has been resolved by using Caputo fractional derivative. The order of fractional derivative μ being considered is 0 < μ ≤ 1, and characterizes the fractality of time. Half-life values have been calculated equivalent with empirical ones. The dependence of fractional derivative order μ on the nuclear structure has also been investigated. [ABSTRACT FROM AUTHOR]

Empirical relations for the preformation probability of cluster decay process in terms of the Q-value, mass asymmetry (η), mass number of the emitted cluster A2 is analyzed based on the discrepancy between the calculated and experimental half-lives of the cluster emitters. For the different empirical expressions considered corresponding to different physical quantities the preformation probability for the complete binary breakup of 226Ra is calculated and the obtained results are compared with the preformed cluster model calculation (P0(PCM) and another calculation in which the overlapping penetration probability is treated as the preformation probability (P0(μ)). Our empirical results for the use of Q-value compare well with P0(μ). Results due to the use of Q and its powers along with the combination of mass number A2 of the cluster emitted, and mass asymmetry η, reveal that preformation factor depends strongly on Q-value rather than A2 and η. Calculated half-lives of different cluster decays for the use of empirical P0 values are found to be in good agreement with the experimental values. [ABSTRACT FROM AUTHOR]

We study the half-lives of some nuclei via the alpha-decay process in ground-state to ground-state (→) transitions. To go through the problem, we consider the parabola and WKB approximations to fin the penetration probability. This new formula is used to evaluate alpha-decay half-lives and a good agreement with the experiment is obtained. [ABSTRACT FROM AUTHOR]

The alpha-decay half-lives of the 24 isotopes of Eu (Z = 63) nuclei in the region 130≤A≤153, have been studied systematically within the Coulomb and proximity potential model (CPPM). We have modified the assault frequency and re-determined the half-lives and they show a better agreement with the experimental value. We have also done calculations on the half-lives within the recently proposed Coulomb and proximity potential model for deformed nuclei (CPPMDN). The computed half-lives are compared with the experimental data and they are in good agreement. Using our model, we could also demonstrate the influence of the neutron shell closure at N = 82, in both parent and daughter nuclei, on the alpha-decay half-lives. [ABSTRACT FROM AUTHOR]

In this paper, the heavy cluster half-lives were calculated using the Wentzel-Kramers-Brillouin (WKB) method. First, we have considered the cluster and daughter nuclei as spherical and the half-lives have been obtained. Then, we have assumed two nuclei as deformed ones and calculations have been performed once again. Deformations of the emitted cluster and daughter nucleus have been presented in terms of elongation and neck thickness parameters. We investigated the influence of elongation and neck thickness parameters on cluster decay half-lives. Our results show that half-lives are affected by these parameters and obtained results for deformed nuclei are in better agreement with experimental data. [ABSTRACT FROM AUTHOR]

The alpha particle preformation and the penetration probability by the Yukawa proximity potential in the even-even nuclei from 178Pb to 238U are studied. Using the experimental values of the alpha decay half-lives and the decay energies, we extract the preformation factors and the penetration probabilities. We also calculate the assault frequencies and the decay constants. The obtained results are motivating. [ABSTRACT FROM AUTHOR]

We intend to study the alpha-decay half-lives of some nuclei from ground state to ground state. We consider a potential model with Yukawa proximity potential. We see that the results are in good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

The ground state and first intrinsic excited state of superheavy nuclei with Z = 120 and N = 160–204 are investigated using both nonrelativistic Skyrme–Hartree–Fock (SHF) and the axially deformed relativistic mean field (RMF) formalisms. We employ a simple BCS pairing approach for calculating the energy contribution from pairing interaction. The results for isotopic chain of binding energy (BE), quadrupole deformation parameter, two neutron separation energies and some other observables are compared with the finite range droplet model (FRDM) and some recent macroscopic–microscopic calculations. We predict superdeformed ground state solutions for almost all the isotopes. Considering the possibility of magic neutron number, two different modes of α-decay chains 292120 and 304120 are also studied within these frameworks. The Qα-values and the half-life Tα½ for these two different modes of decay chains are compared with FRDM and recent macroscopic-microscopic calculations. The calculation is extended for the α-decay chains of 292120 and 304120 from their excited state configuration to respective configuration, which predicts long half-life Tα½ (in seconds). [ABSTRACT FROM AUTHOR]

Calculations of half-lives of superheavy nuclei (SH) show an unexpected result: For some of them heavy particle radioactivity (HPR) dominates over α decay (branching ratios larger than 1). The new mass table AME11 and the theoretical KTUY05 and FRDM95 masses are used to determine Q-values. For Z = 124 we found isotopes with half-lives in the range of ns to ps. [ABSTRACT FROM AUTHOR]

We intend to study the half-lives of Bismuth isotopes via the alpha decay process. To go through the problem, we consider a potential model in which an angle-dependence is considered. Our results reveal that taking into account the multipole approximations for both parent and daughter nuclei will improve the results. [ABSTRACT FROM AUTHOR]

Decay properties and stability of heaviest nuclei with Z≤132 are studied within the macro-microscopical approach for nuclear ground state masses and phenomenological relations for the half-lives with respect to α-decay, β-decay and spontaneous fission. We found that at existing experimental facilities the synthesis and detection of nuclei with Z>120 produced in fusion reactions may be difficult due to their short half-lives (shorter than 1 μs). The nearest (more neutron-rich) isotopes of superheavy elements with 111≤Z≤115 to those synthesized recently in Dubna in 48Ca-induced fusion reactions are found to be β+-decaying. This fact may significantly complicate their experimental identification. However it gives a chance to synthesize in fusion reactions the most stable superheavy nuclei located at the center of the island of stability. Our calculations yield that the β-stable isotopes 291Cn and 293Cn with a half-life of about 100 years are the longest-living superheavy nuclei located at the island of stability. [ABSTRACT FROM AUTHOR]

We review the particle physics aspects of neutrino-less double beta decay. This process can be mediated by light massive Majorana neutrinos (standard interpretation) or by something else (non-standard interpretations). The physics potential of both interpretations is summarized and the consequences of future measurements or improved limits on the half-life of neutrino-less double beta decay are discussed. We try to cover all proposed alternative realizations of the decay, including light sterile neutrinos, supersymmetric or left-right symmetric theories, Majorons, and other exotic possibilities. Ways to distinguish the mechanisms from one another are discussed. Experimental and nuclear physics aspects are also briefly touched, alternative processes to double beta decay are discussed, and an extensive list of references is provided. [ABSTRACT FROM AUTHOR]

Half-lives $T_{1/2}^{2\nu}$ for two-neutrino positron double beta decay modes β+EC/ECEC are calculated for 84Sr, a nucleus of current experimental interest, within the framework of the deformed shell model based on Hartree-Fock states employing a modified Kuo interaction in (2p3/2, 1f5/2, 2p1/2, 1g9/2) space. For a reasonable description of the spectra of 84Sr and 84Kr and to generate allowed GT strengths, the single particle energies of the proton and neutron 1g9/2 orbitals, relative to the 2p3/2 orbital energy, are chosen to be 3.5 MeV and 1.5 MeV for both 84Sr and 84Rb and 1.5 MeV and 1.5 MeV for 84Kr. With this, the calculated half-lives for the β+EC and ECEC modes are ~1026yr and ~4×1024yr respectively. [ABSTRACT FROM AUTHOR]

From an adjustment on a recent selected data set of partial α-decay half-lives of 344 ground state to ground state transitions, analytic formulae are proposed depending on the angular momentum of the α particle. In particular, an expression allows to reproduce precisely the partial α-decay half-lives of even-even heavy nuclei and, then, to predict accurately the partial α-decay half-lives of other very heavy elements from the experimental or predicted Qα. Simple expressions are also provided to calculate the potential barrier radius and height. [ABSTRACT FROM AUTHOR]

Studying the weak nuclear response, especially the Gamow-Teller (GT) transitions, of stable as well as unstable pf-shell nuclei, is one of the key issues in nuclear and astro-nuclear physics. We study the decay half-lives and the GT transitions starting from Tz = ±1 and ±2 mirror nuclei, respectively, by means of β decays and complementary hadronic (3He, t) charge-exchange reactions. Under the assumption that isospin is a good quantum number, symmetry is expected for mirror nuclei and the GT transitions starting from the mirror nuclei. The half-lives and branching ratios and the measured strength distributions of GT transitions are compared and also combined for the understanding of the nuclear structure of pf-shell nuclei far-from-stability. [ABSTRACT FROM AUTHOR]

Theoretical tools at the level of the mean field approximation are used to explore the spontaneous fission properties of odd-A nuclei. The tools rely on the equal (or uniform) filling approximation to deal with the unpaired nucleon in a time-reversal preserving manner. Realistic calculations have been carried out with the finite range Gogny force D1S, which was tailored to reasonably reproduce fission properties in the actinides. The preliminary results obtained for the nucleus 235U are analyzed and the physical origin for the hindrance factor for the spontaneous fission half life is discussed. [ABSTRACT FROM AUTHOR]

A detailed and complete theoretical analysis of an α-decay genetic chain of a superheavy nucleus is performed. A well established chain of the nucleus 269Ds is chosen. The analysis is done in a macroscopic-microscopic approach. [ABSTRACT FROM AUTHOR]

We examine the fission barriers, mass parameters and spontaneous fission half lives of Fermium isotopes within the framework of the macroscopic-microscopic model with a δ-pairing interaction. Four different macroscopic models are applied and studied. The results are compared to experimental data and to the ones of the corresponding monopole pairing approach. The half lives obtained in the δ-pairing model are comparable with experimental data. [ABSTRACT FROM AUTHOR]