arXiv subjects

Yibin Qian

Publications and source records attributed to Yibin Qian.

3 recordsLinked to original sources

arXiv2026

Three-Body Barrier Dynamics of Double-Alpha Decay in Heavy Nuclei

The simultaneous emission of two $α$ particles--double-$α$ decay--represents a long-predicted but unobserved mode of nuclear radioactivity. Here we formulate this process as a genuine three-body problem within the hyperspherical coordinate framework and evaluate decay probabilities by numerically solving the corresponding hyperradial Schrödinger equation, combined with large-scale random sampling of the potential parameters; the latter treatment ensures that the present results are more convincing. Inspired by this, we demonstrate that the penetrability ratio between simultaneous and sequential $α$ emission exhibits a strikingly linear dependence on $ZQ_{αα}^{-1/2}$, extending the barrier penetration dynamics into the correlated few-body regime. The nuclei $^{108}$Xe, $^{218}$Ra, $^{224}$Pu, $^{222}$U, $^{216}$Rn, and $^{220}$Th are suggested as the most promising candidates for the observation of double-$α$ decay, with predicted half-lives potentially accessible within present detection limits. Our results provide a unified framework for multi-$α$ decay and open a pathway to probing nuclear clustering and few-body correlations in heavy nuclei.

nucl-th↗

arXiv2020

Shell evolution in neutron-rich nuclei: the single particle perspective

The shell evolution has been studied extensively within the framework of interacting shell model, while the studies from the single particle viewpoint is relatively lacking or neglected. In particular, the isospin dependence of spin-orbit splitting has become increasingly important as $N/Z$ increases in neutron-rich nuclei. Following the initial independent-particle strategy towards explaining the occurrence of magic numbers, we have systematically investigated the isospin effect on the shell evolution of neutron-rich nuclei within the Woods-Saxon (WS) mean-field potential plus the spin-orbit term. It is found that new magic numbers $N = 14$ and $N =16$ may emerge in neutron-rich nuclei if one changes the sign of the isospin-dependent term in the spin-orbit coupling while the traditional magic number $N = 20$ may disappear. The magic number $N = 28$ is expected to be destroyed despite the sign choice of the isospin part in spin-orbit splitting, while $N = 50$ may disappear and $N = 82$ persists within the single particle scheme. Besides, an appreciable amount of energy gap appears at $N = 32$ and 34 in neutron-rich Ca isotopes. All these results are more consistent with those of the interacting shell model, when the sign of the isospin term of the WS potential is different from that of the corresponding spin-orbit coupling part. The present study may provide a more reasonable starting point for not only the interacting shell but also other nuclear many-body calculations towards the neutron-dripline.

nucl-th↗

arXiv2014

Half-lives of $α$ decay from natural nuclides and from superheavy elements

Recently, experimental researches on the $α$ decay with long lifetime are one of hot topics in the contemporary nuclear physics [e.g. N. Kinoshita {\sl et al.} (2012) and J. W. Beeman {\sl et al.} (2012) ]. In this study, we have systematically investigated the extremely long-lived $α$-decaying nuclei within a generalized density-dependent cluster model involving the experimental nuclear charge radii. In detail, the important density distribution of daughter nuclei is deduced from the corresponding experimental charge radii, leading to an improved $α$-core potential in the quantum tunneling calculation of $α$-decay width. Besides the excellent agreement between theory and experiment, predictions on half-lives of possible candidates for natural $α$ emitters are made for future experimental detections. In addition, the recently confirmed $α$-decay chain from $^{294}$117 is well described, including the attractive long-lived $α$-decaying $^{270}$Db, i.e., a positive step towards the "island of stability" in the superheavy mass region.

nucl-th↗