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New extended method for ψ' scaling function of inclusive electron scattering

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中国科学:物理学、力学、天文学英文版 2023年第10期66卷 53-61页

作者： Lei Wang Qinglin Niu Jinjuan Zhang Jian Liu zhongzhou ren School of Physics Science and Engineering Tongji UniversityShanghai 200092China College of Science China University of Petroleum(East China)Qingdao 266580China College of Electronic and Information Engineering Shandong University of Science and TechnologyQingdao 266590China Laboratory of High Precision Nuclear Spectroscopy Insititute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology Guangxi Normal UniversityGuilin 541004China Key Laboratory of Advanced Micro-Structure Materials Ministry of EducationShanghai 200092China

Scaling analyses have been successfully applied to study the inclusive electron scattering(e, e') over the past few decades. In this study, we utilize the ψ' scaling function in momentum space to analyze the(e, e') cross sections, where the nucleon momentum distributions are derived from self-consistent mean-field calculations. By further introducing the energy and momentum conservation in the scaling analysis, an improved ψ'scaling function is proposed to investigate the high-momentum part of the momentum distributions. Using the proposed scaling function, we systematically explore the effects of the nucleon-nucleon short-range correlation(NN-SRC) on the(e, e') cross sections. From the experimental(e, e') data, the NN-SRC strength is further extracted within the framework of the improved ψ'scaling function. The studies in this paper offer a new method to investigate the nucleon momentum distributions and the NN-SRC effects in nuclei.

关键词： inclusive electron scattering scaling analysis nucleon momentum distribution nucleon-nucleon correlation

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

Theoretical predictions on cluster radioactivity of superheavy nuclei with Z=119,120

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Chinese Physics C 2024年第1期48卷 125-137页

作者：刘洁洁王震张涵韬任中洲 School of Physics Science and Engineering Tongji UniversityShanghai 200092China Key Laboratory of Advanced Micro-Structure Materials Ministry of EducationShanghai 200092China

In this study,we investigate the cluster radioactivity(CR)of new superheavy elements with Z=119 and 120 based on two successful theoretical methods with modified parameters:the density-dependent cluster model(DDCM)and unified decay formula(UDF).First,we employ the DDCM and UDF to accurately reproduce the experimental half-lives of cluster emissions,which demonstrates the high reliability of our theoretical methods.Then,we systematically predict the probable cluster modes of ^(293-311)119 and ^(293-302)120 as well as their corresponding decay energies and half-lives.The half-lives of cluster decay derived from the DDCM are consistent with those from the UDF.Therefore,our results reveal that the cluster emission of ^(8)Be,emitted from the Z=119 and 120 isotopic chains,exhibits the minimum half-life for cluster emission,and hence,^(8)Be emission is considered the most probable cluster decay mode.Moreover,we explore the competition betweenαdecay and CR and find thatαdecay may be the dominant decay mode against CR.Furthermore,the good linear relationship between the decay energy and the number ofαparticles within the emitted cluster is extended to the range of superheavy nuclei(SHN).We anticipate that our theoretical predictions for CR will provide valuable references for the experimental synthesis of new SHN.

关键词： cluster radioactivity superheavy nuclei density-dependent cluster model

Nucleon momentum distribution of 56Fe from the axially deformed relativistic mean-field model with nucleon-nucleon correlations

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Science China(Physics,Mechanics & Astronomy) 2021年第9期64卷 29-40页

作者： Xuezhi Wang Qinglin Niu Jinjuan Zhang Mengjiao Lyu Jian Liu Chang Xu zhongzhou ren College of Science China University of Petroleum(East China)Qingdao 266580China College of Electronic and Information Engineering Shandong University of Science and TechnologyQingdao 266590China College of Science Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Physics Nanjing UniversityNanjing 210093China School of Physics Science and Engineering Tongji UniversityShanghai 200092China

Nucleon momentum distribution(NMD), particularly its high-momentum components, is essential for understanding the nucleonnucleon(NN) correlations in nuclei. Herein, we develop the studies of NMD of 56Fe from the axially deformed relativistic mean-field(RMF) model. Moreover, we introduce the effects of NN correlation into the RMF model from phenomenological models basing on deuteron and nuclear matter. For the region k kF, the high-momentum components of the RMF model are modified by the effects of NN correlation, which agree with the experimental data. Comparing the NMD of relativistic and non-relativistic mean-field models, the relativistic effects on nuclear structures in momentum space are analyzed. Finally, by analogizing the tensor correlations in deuteron and Jastrow-type correlations in nuclear matter, the behaviors and contributions of NN correlations in 56Fe are further analyzed, which helps clarify the effects of the tensor force on the NMD of heavy nuclei.

关键词： nucleon momentum distribution deformed relativistic mean-field model nucleon-nucleon correlations

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 doubleβ--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,doubleβ+-decay(β+β+)with emission of both two positrons and two neutrinos has not been observed up to date.In this article,we perform a systematic analysis on the candidates of doubleβ+-decay,based on the 2012 nuclear mass table.Eight nuclei are found to be the good candidates for doubleβ+-decay and their half-lives are predicted according to the generalization of the systematic law to doubleβ+-decay.As far as we know,there is no theoretical result on doubleβ+-decay of nucleus154Dy and our result is the first prediction on this nucleus.This is also the first complete research on eight doubleβ+-decay candidates based on the available data of nuclear masses.It is expected that the calculated half-lives of doubleβ+-decay in this article will be useful for future experimental search of doubleβ+-decay.

关键词：半衰期中微子衰变物理学系统正电子候选人法律

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 nuclei.Then 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 long.The 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

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

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中国科学：物理学、力学、天文学英文版 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 frame 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 11Be 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：伽莫夫原子核计算壳模型衰变实验数据壳层模型激发能量

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 α-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：模型推导概率成型过程同位素链半衰期壳效应放射性质子数

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 interaction.Both particle-hole and particle-particle residual interactions are consistently introduced in dealing with the pnQRPA matrix equation.The sensitivity of the calculated half-lives to some physical quantities used in the calculations is examined.Calculations are performed for even-even neutron-deficient isotopes ranging from Z = 10 to Z = 76.Good 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 results.Predictions on the β-decay half-lives of some very neutron-deficient nuclei are also given for reference in future experiments.

关键词：计算结果丰质子核半衰期衰变剩余相互作用缺中子同位素准粒子电子捕获