Universal decay law in charged-particle emission and exotic cluster radioactivity

Recent Progress in Two-proton Radioactivity

During the last few decades, rare isotope beam facilities have provided unique data for studying the properties of nuclides located far from the beta-stability line. Such nuclei are often accompanied by exotic structures and radioactive modes, which represent the forefront of nuclear research. Among them, two-proton (2p) radioactivity is a rare decay mode found in a few highly proton-rich isotopes. The 2p decay lifetimes and properties of emitted protons hold invaluable information regarding the nuclear structures in the presence of a low-lying proton continuum; as such, they have attracted co…

The landscape of two-proton radioactivity

Ground-state two-proton (2p) radioactivity is a decay mode found in isotopes of elements with even atomic numbers located beyond the two-proton drip line. So far, this exotic process has been experimentally observed in a few light and medium-mass nuclides with Z less than or equal to 30. In this study, using state-of-the-art nuclear density functional theory, we globally analyze 2p radioactivity and for the first time identify 2p decay candidates in elements heavier than strontium. We predict a few cases where the competition between 2p emission and alpha decay may be observed. In nuclei above…

探究$^{38,39}$Ti可能的双质子放射性

Exploring the possible two-proton radioactivity of $^{38,39}$Ti

本研究利用Gamow壳模型与Gamow耦合道方法分析$^{38,39}$Ti的双质子放射性，证实$^{39}$Ti为可行候选核且价质子有配对倾向，发现$^{38}$Ti是更具潜力的双质子衰变候选核。

Charged Particle Emissions in High-Frequency Alternative Electric Fields

Proton emission, $α$ decay, and cluster radioactivity play an important role in nuclear physics. We show that high-frequency alternative electric fields could deform Coulomb barriers that trap the charged particle, and raise the possibility of speeding up charged particle emissions. They could also cause anisotropic effects in charged particle emissions, and introduce additional terms in the Geiger-Nuttall laws. Our study may further suggest that, for proton emitters like $^{166}$Ir, when the electric field is strong, the dominant decay mode could be changed from $α$ decay to proton emission. …

变形核中质子放射性的微观光学势：纳秒级寿命$^{149}$Lu中一种新颖的角度依赖发射机制

Proton radioactivity in deformed nuclei with microscopic optical potential: A novel angular-dependent emission mechanism in the nanosecond-lived $^{149}$Lu

结合微观光学势与WKB穿透概率及谐振子启发的新方案，预测了$^{149}$Lu中质子发射的小角度禁区现象，理论半衰期与实验吻合，并扩展至其他同位素。

Direct Neutrino Mass Experiments and Exotic Charged Current Interactions

We study the effect of exotic charged current interactions on the electron energy spectrum in tritium decay, focussing on the KATRIN experiment and a possible modified setup that has access to the full spectrum. Both sub-eV and keV neutrino masses are considered. We perform a fully relativistic calculation and take all possible new interactions into account, demonstrating the possible sizable distortions in the energy spectrum.

7Be charge exchange between 7Be3+ ion and exotic long-lived negatively charged massive particle in big bang nucleosynthesis

The existence of an exotic long-lived negatively charged massive particle, i.e., X-, during big bang nucleosynthesis can affect primordial light element abundances. Especially, the final abundance of 7Li, mainly originating from the electron capture of 7Be, has been suggested to reduce by the 7Be destruction via the radiative X- capture of 7Be followed by the radiative proton capture of the bound state of 7Be and X- (7BeX). We suggest a new route of 7BeX formation, that is the 7Be charge exchange at the reaction of 7Be3+ ion and X-. The formation rate depends on the number fraction of 7Be3+ io…

Nuclear aspects of neutral current non-standard $ν$-nucleus reactions and the role of the exotic $μ^-\to e^{-}$ transitions experimental limits

The nuclear aspects of flavour changing neutral current (FCNC) processes, predicted by various new-physics models to occur in the presence of nuclei, are examined by computing the relevant nuclear matrix elements within the context of the quasi-particle RPA using realistic strong two-body forces. One of our aims is to explore the role of the non-standard interactions (NSI) in the leptonic sector and specifically: (i) in lepton flavour violating (LFV) processes involving the neutral particles $ν_\ell$ and $\tildeν_\ell$, $\ell = e,μ,τ$ and (ii) in charged lepton flavour violating (cLFV) process…

核靶上光子诱导产生奇特带电类粲偶素态 $Z_c(3900)$ 及其内部结构

Photon-induced production of the exotic charged charmonium-like state $Z_c(3900)$ off nuclear targets and its internal structure

本文利用基于核谱函数的光子诱导核碰撞模型，计算$Z_c(3900)^{\pm}$在不同核靶、能量和角度下的产生截面及A依赖性，以区分其四夸克、分子态或混合内部结构。

Charged charmonium-like structures and the initial single chiral particle emission mechanism

This paper summarizes what we have done so far to explain charged charmonium/bottomonium-like structures using a hadronic triangle diagram which we call the initial single chiral particle emission mechanism. We discuss processes like $A\to A'+P+P'$ in which two chiral particles $P$ and $P'$ are emitted from $A$. In the intermediate we consider a hadronic one-loop diagram in which $D^{(*)}/D_s^{(*)}/B^{(*)}/B_s^{(*)}$ are included to explain some enhancements experimentally observed. Using this mechanism we explain some of the exotic enhancements and predict a couple of enhancement structures.