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Half-lives of double β^+-decay with two neutrinos

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Science China(Physics,Mechanics & Astronomy) 2015年第1期58卷 38-41页

作者： ren YueJiao ren zhongzhou Department of Physics Nanjing University Center of Theoretical Nuclear Physics National Laboratory of Heavy-Ion Accelerator

Nuclear double β^--decays with two neutrinos were observed for many years and a systematic law describing the relation between their half-lives and decay energies was also proposed recently [Phys Rev C, 2014, 89： 064603]. However, double β^＋ -decay （β^＋β^＋） with emission of both two positrons and two neutrinos has not been observed up to date. In this article, we pcrform a systematic analysis on the candidates of double β^＋-decay, based on the 2012 nuclear mass table. Eight nuclei are found to be the good candidates for double β^＋-decay and their half-lives are predicted according to the generalization of the systematic law to double β^＋-decay. As far as we know, there is no theoretical result on double β^＋-decay of nucleus ^154Dy and our result is the first prediction on this nucleus. This is also the first complete research on eight double β^＋-decay candidates based on the available data of nuclear masses. It is expected that the calculated half-lives of double β^＋-decay in this article will be useful for future experimental search of double β^＋-decay.

关键词： double β^+-decay with two neutrinos half-lives systematic law weak interaction.

New Geiger-Nuttall law of odd-Z nuclei and long-lived island beyond the stable line

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Nuclear Science and Techniques 2013年第5期24卷 92-97页

作者： ren Yuejiao ren zhongzhou Department of Physics Nanjing University

Recently,we analyze the α-decay data of even-Z nuclei and propose the new Geiger-Nuttall law where the effects of the quantum numbers of α-core relative motion are naturally embedded in the law [Physical Review C 85,044608(2012)].In this paper,we firstly test whether the new law without any change of parameters can be applied to the α-decays of odd-Z nuclei which are more complicated than those of even-even *** the nuclear shell effect around N=126 is analyzed for very proton-rich nuclei with Z=85-92 based on the data of α-decay energies and half-lives.A long-lived island beyond the stable line is proposed where the half-lives of nuclei on this island are abnormally *** mechanism of the appearance of the island and its significance to other mass ranges are discussed.

关键词：长寿命稳定塔衰变数据相对运动质量范围嵌入法量子数

Alpha-clustering effects in heavy nuclei

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Frontiers of physics 2018年第6期13卷 133-144页

作者： zhongzhou ren Bo Zhou School of Physics Science and Engineering Tongji University Shanghai 200092 China Institute for International Collaboration Hokkaido University Sapporo 060-0815 Japan

The study of cluster structures in light nuclei is extending to the heavy nuclei in these years. As for the stable N = Z nuclei, from the lighter 8Be, 12C nuclei to the heavier 20Ne and even the 40Ca and 44Ti medium nuclei, the a cluster structures have been well studied and confirmed. In heavy nuclei, due to the dominated mean field, the existence of α cluster structure is not clear as light nuclei but some clues were found for indicating the core＋ α cluster structure in some nuclei, in particular, the 208 pb＋α structure in 212Po. We review some recent progress about the theoretical and experimental explorations of the a-clustering effects in heavy nuclei. We also discuss the possible a cluster structure of heavy nuclei from the view of a decay.

关键词： α cluster structure nuclear cluster model α correlations α decay

Shell model calculations for the allowed Gamow-Teller β-decays of light nuclei

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Science China(Physics,Mechanics & Astronomy) 2014年第6期57卷 1005-1012页

作者： LI HanTao ren zhongzhou Department of Physics and Key Laboratory of Modern Acoustics Institute of AcousticsNanjing University Joint Center of Nuclear Science and Technology Nanjing University Center of Theoretical Nuclear Physics National Laboratory of Heavy-Ion Accelerator

The allowed Gamow-Teller β-decay information of Li, Be, B, C, and N isotopes under the flame work of nuclear shell model is calculated herein. Theoretical results of Q values, half-lives, excitation energies, log ft values, branching fractions, and β-delayed proton/neutron emission probabilities are tabulated and compared with experimental data. The deviations from the observations are also analyzed. The llBe nucleus is well known for its anomaly ground state Jπ=1/2＋. Thus, we compared the theoretical energy levels with the experimental data and the agreements for low excitation states are consistent. The quenching factor is also evaluated and discussed.

关键词： light nuclei Gamow-Teller β-decay nuclear shell model

Model-independent trend of α-preformation probability

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Science China(Physics,Mechanics & Astronomy) 2013年第8期56卷 1520-1524页

作者： QIAN YiBin ren zhongzhou Department of Physics Nanjing University Joint Center of Nuclear Science and Technology Nanjing University Kavli Institute for Theoretical Physics China Center of Theoretical Nuclear Physics National Laboratory of Heavy-Ion Accelerator

The α-preformation probability is directly deduced from experimental α decay energies and half-lives in an analytical way without any modified parameters. Several other model-deduced results, are used to compare with that of the present study. The key role played by the shell effects in the v-preformation process is indicated in all these cases. In detail, the α-preformation factors of different theoretical extractions are found to have similar behavior for one given isotopic chain, implying the model-independent varying trend of the preformation probability of α particle. In addition, the formation probability of heavier particle in cluster radioactivity is also obtained, and this confirms the relationship between the cluster preformation factor and the product of the cluster and daughter proton numbers.

关键词： α decay preformation factor cluster model

Calculations of β-decay half-lives of proton-rich nuclei

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Science China(Physics,Mechanics & Astronomy) 2012年第12期55卷 2397-2406页

作者： NI DongDong ren zhongzhou ZHI QiJun Department of Physics Nanjing UniversityNanjing 210093China Kavli Institute for Theoretical Physics China Beijing 100190China Center of Theoretical Nuclear Physics National Laboratory of Heavy-Ion AcceleratorLanzhou 730000China GSI Helmholtzzentrum für Schwerionenforschung DarmstadtGermany School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China

We investigate the half-lives of β + /EC(electron capture) decay using the proton-neutron quasiparticle random-phase approximation(pnQRPA) with a δ-form Gamow-Teller residual *** particle-hole and particle-particle residual interactions are consistently introduced in dealing with the pnQRPA matrix *** sensitivity of the calculated half-lives to some physical quantities used in the calculations is *** are performed for even-even neutron-deficient isotopes ranging from Z = 10 to Z = *** agreement between experiment and theory is achieved especially for the nuclei far from stability,and the results of our calculations are discussed with comparison with other theoretical *** on the β-decay half-lives of some very neutron-deficient nuclei are also given for reference in future experiments.

关键词： proton-rich nuclei β-decay half-lives quasiparticle random-phase approximation

Monogamy quantum correlation near the quantum phase transitions in the two-dimensional XY spin systems

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Chinese Physics B 2018年第6期27卷 137-144页

作者： Meng Qin zhongzhou ren Xin Zhang Department of General Education Army Engineering University of PLA Nanjing 211101 China Department of Physics Nanfing University Nanjing 210093 China School of Physics Science and Engineering Tongji University Shanghai 200092 China

We investigate the role of quantum correlation around the quantum phase transitions by using quantum renormalization group theory. Numerical analysis indicates that quantum correlation as well as quantum nonlocality can efficiently detect the quantum critical point in the two-dimensional XY systems. The nonanalytic behavior of the first derivative of quantum correlation is observed at the critical point as the size of the model increases. Furthermore, we discuss the quantum correlation distribution in this system based on the square of concurrence（SC） and square of quantum discord（SQD）. The monogamous properties of SC and SQD are obtained. Particularly, we prove that the quantum critical point can also be achieved by monogamy score.

关键词： XY model quantum phase transitions quantum correlation monogamy relation

Dynamical stable-jump–stable-jump picture in a non-periodically driven quantum relativistic kicked rotor system

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Chinese Physics B 2019年第2期28卷 156-160页

作者： Hsincheng Yu zhongzhou ren Xin Zhang Department of Physics Nanjing University School of Physics Science and Engineering Tongji University

We study a non-periodically driven kicked rotor based on the one-dimensional quantum relativistic kicked rotor(QRKR). In our model, we add a small constant to the interval of the one-dimensional QRKR after each kick *** is found that the momentum spreading is stable in finite kicked times, it then jumps up or down and becomes stable *** interesting phenomenon is understood by quantum resonance. Moreover, the stable-jump–stable-jump phenomenon persists, even though the interval of kick process is randomly increased. This result means that the quantum resonance is independent of the periodic perturbation in the QRKR model.

关键词： quantum chaos dynamical localization quantum resonance

Research on two-proton radioactivity in density-dependent cluster model

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Science China(Physics,Mechanics & Astronomy) 2023年第2期66卷 59-67页

作者： Ziyi Yuan Dong Bai Zhen Wang zhongzhou ren Dongdong Ni School of Physics Scienceand Engineering Tongji UniversityShanghai 200092China Collegeof Science Hohai UniversityNanjing211100China Key Laboratory of Advanced Micro-Structure Materials Ministry of EducationShanghai 200092China State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacao 9078China

The density-dependent cluster model(DDCM) provides a unified framework to study α decay,heavy-cluster radioactivity,and proton ***-proton(2p) radioactivity is a rare decay mode of exotic nuclei near or beyond the *** is of great interest to explore the applicability of DDCM to this exotic decay *** this work,DDCM has been extended to study 2p *** 2p-radioactivity half-lives are calculated for several known 2p-emitters,including19Mg,45Fe,48Ni,54Zn,*** theoretical results are in good agreement with the experimental data,with the standard deviations comparable to or smaller than those given by some other theoretical models and empirical *** also predict the half-lives of a number of possible 2p-emitters with S2p 0 using the new data from AME2020 and *** predictions serve as useful references for future experimental and theoretical investigations on 2p radioactivity.

关键词： cluster radioactivity decay