检索结果-南通市图书馆

A phenomenological equation of state for isospin asymmetric nuclear matter

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2009年第10期52卷 1494-1505页

作者： CHEN LieWen1,2 1 Department of physics,Shanghai Jiao Tong University,Shanghai 200240,china 2 Center of theoretical {3. physics,national laboratory of heavy ion Accelerator,lanzhou 73.000,china Department of physics Shanghai Jiao Tong University Shanghai 200240 China Center of theoretical nuclear physics National Laboratory of Heavy Ion Accelerator Lanzhou 730000 China

A phenomenological momentum-independent(MID) model is constructed to describe the equation of state(EOS) for isospin asymmetric nuclear matter,especially the density dependence of the nuclear symmetry energy Esym(ρ).This model can reasonably describe the general properties of the EOS for symmetric nuclear matter and the symmetry energy predicted by both the sophisticated isospin and momentum dependent MDI model and the Skyrme-Hartree-Fock *** find that there exists a nicely linear correlation between Ksym and L as well as between J0/K0 and K0,where L and Ksym represent,respectively,the slope and curvature parameters of the symmetry energy at the normal nuclear density ρ0,while K0 and J0 are,respectively,the incompressibility and the third-order derivative parameter of symmetric nuclear matter at ρ*** correlations together with the empirical constraints on K0,L and Esym(ρ0) lead to an estimation of -477 MeV Ksat,2 -241 MeV for the second-order isospin asymmetry expansion coefficient for the incompressibility of asymmetric nuclear matter at the saturation point.

关键词： equation of state of nuclear matter isospin the symmetry energy

Eigenvalues of Large Matrices

在线全文

学校读者我要写书评

暂无评论

原子核物理评论 2009年第S1期26卷 165-167页

作者： ZHAO Yu-min1,2 (1 Department of physics, Shanghai Jiaotong University, Shanghai 200240,china 2 Center of theoretical {3. physics, national laboratory of heavy ion research facility in lanzhou, lanzhou 73.000, china)

We recently performed a series of improvement on evaluation of eigenvalues without complicated iterations. In this work we first discuss evaluation of the lowest eigenvalue for given systems,by which one conveniently obtains the value of the lowest eigenvalue based on the dimension and width of given matrix. We also discuss a strong correlation between eigenvalues and diagonal matrix elements for large matrices,by which one is able to predict eigenvalues approximately without iterations.

关键词： eigenvalue large matrix correlation

Higher order bulk characteristic parameters of asymmetric nuclear matter

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2011年第S1期54卷 124-129页

作者： CHEN LieWen1,2 1Department of physics, Shanghai Jiao Tong University, Shanghai 200240, china 2Center of theoretical {3. physics, national laboratory of heavy ion Accelerator, lanzhou 73.000, china 1. Department of physics Shanghai Jiao Tong University Shanghai 200240 China 2. Center of theoretical nuclear physics National Laboratory of Heavy Ion Accelerator Lanzhou 730000 China

The bulk parameters characterizing the energy of symmetric nuclear matter and the symmetry energy defined at normal nuclear density ρ0 provide important information on the equation of state (EOS) of isospin asymmetric nuclear matter. While significant progress has been made in determining some lower order bulk characteristic parameters, such as the energy E0(ρ0) and incompress ibility K0 of symmetric nuclear matter as well as the symmetry energy Esym(ρ0) and its slope parameter L, yet the higher order bulk characteristic parameters are still poorly known. Here, we analyze the correlations between the lower and higher order bulk char acteristic parameters within the framework of Skyrme Hartree-Fock energy density functional and then estimate the values of some higher order bulk characteristic parameters. In particular, we obtain J0 = (-3.5±95) MeV and I0 = (1473.680) MeV for the third order and fourth-order derivative parameters of symmetric nuclear matter at ρ0 and Ksym = (-100 ± 165) MeV, Jsym = (224 ± 3.5) MeV, Isym = (-13.9 ± 2025) MeV for the curvature parameter, third-order and fourth-order derivative parameters of the symmetry energy at ρ0, using the empirical constraints on E0(ρ0), K0, Esym(ρ0), L, and the isoscalar and isovector nucleon effective masses. Furthermore, our results indicate that the three parameters E0(ρ0), K0, and J0 can reasonably characterize the EOS of symmetric nuclear matter up to 2ρ0 while the symmetry energy up to 2ρ0 can be well described by Esym(ρ0), L, and Ksym.

关键词： equations of state of nuclear matter forces in hadronic systems and effective interactions symmetry energy nuclear density functional theory and extensions asymmetric matter neutron matter

The relativistic consistent angular-momentum projected shell model study of the N=Z nucleus ^(52)Fe

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2009年第10期52卷 1471-1476页

作者： LI YanSong1,2 & LONG GuiLu1,2 1 Department of physics,Tsinghua University,Beijing 100084,china 2 Center of nuclear Theory,{3. laboratory of heavy ion Accelerator of lanzhou,lanzhou 73.000,china 1. Department of physics Tsinghua University Beijing 100084 China 2. Center of nuclear Theory National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000 China

The relativistic consistent angular-momentum projected shell model(ReCAPS) is used in the study of the structure and electromagnetic transitions of the low-lying states in the N=Z nucleus *** model calculations show a reasonably good agreement with the *** backbending at 12+ is reproduced and the energy level structure suggests that neutron-proton interactions play important roles.

关键词： ReCAPS relativistic mean field angular-momentum projection method 52Fe neutron-proton interaction

α-decay Branching Ratios to Rotational Band of heavy Even-even and Odd-A Nuclei

在线全文

学校读者我要写书评

暂无评论

原子核物理评论 2009年第S1期26卷 55-58页

作者： REN Zhong-zhou1,2,3.XU Chang2,3.(1 Center of theoretical nuclear physics,{3. laboratory of heavy ion research facility in lanzhou,lanzhou 73.000,china 2 Department of physics,Nanjing University,Nanjing 210008,china 3.Joint Center for Particle,nuclear physics and Cosmology,Nanjing 210008,china) Center of theoretical nuclear physics National Laboratory of Heavy Ion Research Facility in LanzhouLanzhou 730000China Department of physics Nanjing UniversityNanjing 210008China Joint Center for Particle Nuclear Physics and CosmologyNanjing 210008China Department of physics Nanjing UniversityNanjing 210008China Joint Center for Particle Nuclear Physics and CosmologyNanjing 210008China

By using a simple barrier penetration approach,we predict the α-decay branching ratios to members of ground-state rotational band of heavy even-even No isotopes. We also extend our approach to calculate the α-decay branching ratios to the rotational band of heavy odd-A nuclei. The theoretical branching ratios of α-decays are found in good agreement with the available experimental data.

关键词： α-decay branching ratio heavy nuclei

Profile of the composition fractions in neutron stars

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第8期47卷 632-634页

作者： LI Wenfei, ZHANG Fengshou & CHEN LiewenCenter of theoretical nuclear physics, {3. laboratory of heavy ion Accelerator, lanzhou 73.000, china Institute of Modern physics, Chinese Academy of Sciences, lanzhou 73.000, china Department of physics, Shangh Center of theoretical nuclear physics National Laboratory of Heavy Ion Accelerator Lanzhou China Institute of Modern physics Chinese Academy of Sciences Lanzhou China Department of physics Shanghai Jiao Tong University Shanghai China

The composition fractions of β-stable neutron stars and their radial distributions are investigated based on Skyrme-Hartree-Fock theory and Tolman-Oppenheimer-Volkoff (TOV) equation. It is found that a pure neutron interior with a radius of 3.5 km can exist in the neutron stars. When the radius is greater than 3.5 km, the fractions of the proton, electron and μ- appear and increase with the increment of the radius, then decrease after reaching their maximum at the radius of 8 km. These results make it possible to further study the thermal evolution and magnetic properties of the neutron stars.

关键词： neutron stars compositon fractions asymmetric nuclear matter equation of state Tolman-Oppenheimer-Volkoff equation.

Probing nuclear Symmetry Energy with Giant Dipole Resonances in Finite Nuclei

在线全文

学校读者我要写书评

暂无评论

原子核物理评论 2009年第S1期26卷 181-184页

作者： CAO Li-gang1,3.MA Zhong-yu2,3.(1 Institute of Modern physics,Chinese Academy of Sciences,lanzhou 73.000,china 2{3. Institute of Atomic Energy,Beijing 102413.china 3.Center of theoretical nuclear physics,national laboratory of heavy ion research {13. in lanzhou,lanzhou 73.000,china) Institute of Modern physics Chinese Academy of SciencesLanzhou 730000China Center of theoretical nuclear physics National Laboratory of Heavy Ion Research Facility in LanzhouLanzhou 730000China china Institute of Atomic Energy Beijing 102413China Center of theoretical nuclear physics National Laboratory of Heavy Ion Research Facility in LanzhouLanzhou 730000China

The relationship between the centroid energies of the isovector giant dipole resonance of finite nuclei and the symmetry energy has been studied. It is found the excitation energies of the dipole resonance in finite nuclei are correlated linearly with the symmetry energy at and below the saturation density. This linear correlation leads to the symmetry energy at the saturation density at the interval 3..0 MeV ≤ S(ρ0) ≤ 3..0 MeV,and the symmetry energy at ρ = 0.1 fm-3.at the interval 21.2-22.5 MeV. It is proposed that a precise measurement of the dipole mode in nuclei could set up an important constraint on the equation of state for nuclear matter.

关键词： symmetry energy dipole resonance Pygmy resonance

HIRFL and studies of hot nuclei and nuclei far from stability

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第7期42卷 529-541页

作者： LUO YixiaoInstitute of Modern physics, Chinese Academy of Sciences, national laboratory of {3. ion Accelerator of lanzhou, lanzhou 73.000, china Institute of Modern physics Chinese Academy of Sciences National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou China

heavy ion physics has been rapidly developing at the limits of energy ({3. temperature), isospin and spin. heavy ion research facility of lanzhou (HIRFL) is of cyclotron family delivering intermediate energy heavy ions. During the recent years, progress has been made in the studies of heavy ion physics as well as in the development of the HIRFL. This review article will

关键词： heavy ion accelerator radioactive ion beam hot nuclei nuclei far from stability.

Charmed Baryon in Diquark Model

在线全文

学校读者我要写书评

暂无评论

原子核物理评论 2009年第S1期26卷 190-193页

作者： WANG Qing-wu1,3. ZHANG Peng-ming1,2(1 Institute of Modern physics, Chinese Academy of Sciences, lanzhou 73.000, china 2 Center of {3. nuclear physics, national laboratory of heavy ion research facility in lanzhou,lanzhou 73.000, china 3.Graduate School of Chinese Academy of Sciences, Beijing 100049, china) Institute of Modern physics Chinese Academy of SciencesLanzhou 730000China Graduate School of Chinese Academy of Sciences Beijing 100049China Institute of Modern physics Chinese Academy of SciencesLanzhou 730000China Center of theoretical nuclear physics National Laboratory of Heavy Ion Research Facility in LanzhouLanzhou 730000China

A diquark model is used to investigate single-charmed baryons. In this model,baryon is composed of two diquarks and an antiquark. Masses of lowest lying states with JP=1/2± are obtained. Baryons in our results are as heavy as other theoretic predictions and we suggest that the five-quark components should be considered in any three-quark model for studying the charmed baryons.

关键词： charm diquark pentaquark