Systematic study of proton radioactivity of spherical proton emitters within various versions of proximity potential formalisms

Abstract

In this work we present a systematic study of the proton radioactivity half-lives of spherical proton emitters within the Coulomb and proximity potential model. We investigate 28 different versions of the proximity potential formalisms developed for the description of proton radioactivity, α decay and heavy particle radioactivity. It is found that 21 of them are not suitable to deal with the proton radioactivity, because the classical turning points rin cannot be obtained due to the fact that the depth of the total interaction potential between the emitted proton and the daughter nucleus is above the proton radioactivity energy. Among the other 7 versions of the proximity potential formalisms, it is Guo2013 which gives the lowest rms deviation in the description of the experimental half-lives of the known spherical proton emitters. We use this proximity potential formalism to predict the proton radioactivity half-lives of 13 spherical proton emitters, whose proton radioactivity is energetically allowed or observed but not yet quantified, within a factor of 3.71.

Systematic study of α decay half-lives within the Generalized Liquid Drop Model with various versions of proximity energies *

“…When a neck or a gap appears in one-body shapes or between separated fragments, an additional term called the proximity energy must be added to take into account the effects of the nuclear forces between the close surfaces [37,40]. The proximity energy is described as the product of a factor depending on the mean curvature of the interaction surface and a universal function depending on the separation distance [53,54].…”

“…The proximity energies are also used to study the fusion reaction cross sections and nuclear decay (including proton radioactivity, α decay, and cluster radioactivity), because these decay modes proceed in the opposite direction of fusion between a particle or cluster and the daughter nucleus [50,51]. The proximity energy is based on the proximity force theorem [49,52], which is described as the product of a factor depending on the mean curvature of the interaction surface and a universal function (depending on the separation distance) and is independent of the masses of colliding nuclei [53,54]. In the past few decades, numerous works have been devoted to improving the original proximity energy (Prox.…”

“…In the past few decades, numerous works have been devoted to improving the original proximity energy (Prox. 77) [49], by either adopting a better form of the surface energy coefficients [55][56][57][58][59][60][61][62] or introducing an improved universal function or another nuclear radius parameterization [52,53,[63][64][65][66][67][68][69][70][71][72][73][74].…”

Two-proton radioactivity within Coulomb and proximity potential model *

“…For its simple and accurate formalism with the advantage of adjustable parameters, using the proximity potential to replace the nuclear potential, Santhosh et al proposed the Coulomb and proximity potential model (CPPM) [70] to deal with cluster radioactivity in 2002. CPPM [70] was extended to study α decay [61,[71][72][73][74][75], proton radioactivity [16,76], α decay fine structure [77,78], heavy ion fusion and ternary fission [62,63,79,80] and predict the α decay chains of superheavy nuclei [81,82]. Considering that the radioactivity process shares the same theory as α decay and proton radioactivity, i.e., all are barrier penetration processes, it is desirable to ask whether or not the CPPM can be extended to study radioactivity.…”

Diffuseness effect and radial basis function network for optimizing α decay calculations *

“…Although superheavy nuclei (SHN) can be synthesized via cold and hot fusion reactions in experiments [1][2][3], it is challenging to synthesize SHN with and to explore the existence limit for SHN [4][5][6][7][8][9][10]. Therefore, continued research into the stability and decay properties of SHN is crucial [11][12][13][14][15][16][17][18][19]. As one of the dominant decay channels of SHN, decay provides an opportunity to probe the nuclear structure properties of SHN and simultaneously identify new elements via the observation of decay from an unknown parent nucleus to a known daughter nucleus.…”