检索结果-南通市图书馆

Effects of relativistic kinematics in heavy ion elastic scattering

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2014年第2期38卷 29-33页

作者：庞丹阳 School of Physics and Nuclear Energy Engineering Beihang University international research center for nuclei and particles in the cosmos Beihang University

Relativistic corrections to the reaction kinematic parameters were made for elastic scattering of ^6Li, ^12C and ^40Ar from ^40Ca,^90Zr and ^208Pb targets at incident energies between 20 and 100 MeV/nucleon. The results of optical model calculations show that the efects of such corrections are important when describing the angular distributions of elastic scattering cross sections for heavy ion scattering at incident energies as low as around 40 MeV/nucleon. The efects on the total reaction cross sections on the other hand, were found to be small within the energy range studied when the optical model potential is fixed.

关键词： heavy ion elastic scattering optical model relativistic kinematics

Study of fusion Q-value rule in sub-barrier fusion of heavy ions

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2015年第7期39卷 19-25页

作者：刘星星张高龙张焕乔 School of Physics and Nuclear Energy Engineering Beihang University international research center for nuclei and particles in the cosmos Beihang University China Institute of Atomic Energy

A vast body of fusion data has been analyzed for different projectiles and target nuclei. It is indicated that the sub-barrier fusion depends on the fusion Q-value. In terms of a recently introduced fusion Q-value rule and an energy scaling reduction procedure, the experimental fusion excitation functions are reduced and compared with each other. It is found that the reduced fusion excitations of selected fusion systems show a similar trend. The fusion data for massive nuclei are in agreement with the Q-value rule. In the fusion process, the Q contribution should be considered. Within this approach, the sub-barrier fusion cross sections of most fusion systems can be predicted without involving any structure effects of colliding nuclei. Instances of disagreement are presented in a few fusion systems. The use of the energy scaling as a criterion of possible experimental data inconsistency is discussed. More precise experimental fusion data need to be measured.

关键词： compound nuclei,sub-barrier fusion,new energy scaling

A method of estimating and subtracting the hydrogen background in the natural carbon target used in the ^(12)C + ^(12)C experiment

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2014年第5期25卷 63-67页

作者：屈卫卫张高龙 Satoru Terashima Isao Tanihata 郭晨雷乐小云 School of Physics and Nuclear Energy Engineering Beihang University international research center for nuclei and particles in the cosmos Beihang University research center for Nuclear Physics Osaka University

The experimental data of 100 A MeV12C +12C elastic scattering are checked by using two-body kinematic calculation and12 C + p elastic scattering. It is shown that the measured data are true and reliable. In the paper,the transformation between the excited energy spectra of the12 C +12C system and the ground state energy spectra of the12 C + p system is introduced. The method of subtraction of the hydrogen background in the natural carbon target used in the experiment is elaborately described and the results are discussed. It is indicated that this method of subtraction of hydrogen background is reasonable and can be used in the data analysis. Based on the elastic scattering cross section of the previous experiment of12C+p at 95.3A MeV, the hydrogen content entered into the reaction is analyzed. The final hydrogen content in the natural carbon target is(2.73 ± 0.12)%.

关键词：实验数据氢含量碳靶天然弹性散射截面估算运动学计算背景减除

Single particles in a reflection-asymmetric potential

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2018年第8期61卷 61-68页

作者： YuanYuan Wang ZhengXue Ren School of Physics and Nuclear Energy Engineering and international research center for nuclei and particles in the cosmos Beihang University State Key Laboratory of Nuclear Physics and Technology School of Physics Peking University

Single particles moving in a reflection-asymmetric potential are investigated by solving the Schr ¨odinger equation of the reflectionasymmetric Nilsson Hamiltonian with the imaginary time method in 3 D lattice space and the harmonic oscillator basis expansion method. In the 3 D lattice calculation, the l2 divergence problem is avoided by introducing a damping function, and the(l^2) Nterm in the non-spherical case is calculated by introducing an equivalent N-independent operator. The efficiency of these numerical techniques is demonstrated by solving the spherical Nilsson Hamiltonian in 3 D lattice space. The evolution of the single-particle levels in a reflection-asymmetric potential is obtained and discussed by the above two numerical methods, and their consistency is shown in the obtained single-particle energies with the differences smaller than 10^(-4)[hω_0].

关键词：不对称 Hamiltonian 粒子分叉问题数字技术数字方法子空间 3D

Recent development in SU（3） covariant baryon chiral perturbation theory

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2013年第3期8卷 328-348页

作者： Li-Sheng Geng School of Physics and Nuclear Energy Engineering Beihang University Beijing 100191 China international research center for nuclei and particles in the cosmos Beihang University Beijing 100191 China

Baryon chiral perturbation theory （BChPT）, as an effective field theory of low-energy quantum chromodynamics （QCD）, has played and is still playing an important role in our understanding of non-perturbative strong-interaction phenomena. In the past two decades, inspired by the rapid progress in lattice QCD simulations and the new experimental campaign to study the strangeness sector of low-energy QCD, many efforts have been made to develop a fully covariant BChPT and to test its validity in all scenarios. These new endeavours have not only deepened our understanding of some long-standing problems, such as the power-counting-breaking problem and the convergence problem, but also resulted in theoretical tools that can be confidently applied to make robust predic- tions. Particularly, the manifestly covariant BChPT supplemented with the extended-on-mass-shell （EOMS） renormalization scheme has been shown to satisfy all analyticity and symmetry constraints and converge relatively faster compared to its non-relativistic and infrared counterparts. In this article, we provide a brief review of the fully covariant BChPT and its latest applications in the u, d, and s three-flavor sector.

关键词： chiral Lagrangians lattice QCD calculations baryon resonances hyperons

Towards the full realization of the RIBLL2 beam line at the HIRFL-CSR complex

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2018年第2期63卷 78-80页

作者： Bao-Hua Sun Jian-Wei Zhao Xue-Heng Zhang Li-Na Sheng Zhi-Yu Sun Isao Tanihata Satoru Terashima Yong Zheng Li-Hua Zhu Li-Min Duan Liu-Chun He Rong-Jiang Hu Guang-Shuai Li Wen-Jian Lin Wei-Ping Lin Chuan-Ye Liu Zhong Liu Chen-Gui Lu Xin-Wen Ma Li-Jun Mao Yi Tian Feng Wang Meng Wang Shi-Tao Wang Jia-Wen Xia Xiao-Dong Xu Hu-Shan Xu Zhi-Guo Xu Jian-Cheng Yang Da-Yu Yin You-Jin Yuan Wen-Long Zhan Yu-Hu Zhang Xiao-Hong Zhou School of Physics and Nuclear Energy Engineering Beihang University Beijing 100191 China international research center for nuclei and particles in the cosmos Beijing 100191 China Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China

More than 99%of the mass in the visible universe—the material that makes up ourselves,our planet,stars—is in the atomic nucleus.Although the matter has existed for billions of years,only over the past few decades have we had the tools and the knowledge necessary to get a basic understanding of the structure and dynamic of nuclei.Nuclear physicists around the world have made tremendous strides by initiating a broad range of key

关键词： HIRFL-CSR 横梁建筑群排队原子核物理学家试验性世界

Study of hadrons using the Gaussian functional method in the O(4) linear σ model

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2015年第6期39卷 52-63页

作者：陈华星 Shotaro Imai Hiroshi Toki 耿立升 School of Physics and Nuclear Energy Engineering and international research center for nuclei and particles in the cosmos Beihang University Department of Physics Kyoto University Meme Media Laboratory Hokkaido University research center for Nuclear Physics Osaka University

We study properties of hadrons in the O（4） linear σ model, where we take into account fluctuations of mesons around their mean field values using the Gaussian functional （GF） method. In the GF method we calculate dressed σ and π masses, where we include the effect of fluctuations of mesons to find a better ground state wave function than the mean field approximation. Then we solve the Bethe-Salpeter equations and calculate physical σ and π masses. We recover the Nambu-Goldstone theorem for the physical pion mass to be zero in the chiral limit. The σ meson is a strongly correlated meson-meson state, and seems to have a two meson composite structure. We calculate σ and π masses as functions of temperature for both the chiral limit and explicit chiral symmetry breaking case. We get similar behaviors for the physical σ and π masses as the case of the mean field approximation, but the coupling constants are much larger than the values of the case of the mean field approximation.

关键词： linear a model sigma and pion Gaussian functional method Bethe-Salpeter equation Nambu Goldstone theorem finite temperature

Determination of astrophysical ^7Be（p, γ）8B reaction rates from the ^7Li（d, p）^8Li reaction

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2015年第6期58卷 74-80页

作者： DU XianChao GUO Bing LI ZhiHong PANG DanYang LI ErTao LIU WeiPing China Institute of Atomic Energy School of Physics and Nuclear Energy Engineering Beihang University international research center for nuclei and particles in the cosmos Beihang University College of Physics Science and Technology Shenzhen University

The7Be(p,γ)8B reaction plays a central role not only in the evaluation of solar neutrino fluxes but also in the evolution of the first stars.Study of this reaction requires the asymptotic normalization coefficient(ANC) for the virtual decay8 Bg.s.→7Be + p.By using the charge symmetry relation,we obtain this proton ANC with the single neutron ANC of8 Lig.s.→7Li + n,which is determined with the distorted wave Born approximation(DWBA) and adiabatic distorted wave approximation(ADWA) analysis of the7Li(d,p)8Li angular distribution.The astrophysical S-factors and reaction rates of the direct capture process in the7Be(p,γ)8B reaction are further deduced at energies of astrophysical relevance.The astrophysical S-factor at zero energy for direct capture,S17(0),is derived to be(19.9±3.5) e V b in good agreement with the most recent recommended value.The contributions of the1+and 3+resonances to the S-factor and reaction rate are also evaluated.The present result demonstrates that the direct capture dominates the7Be(p,γ)8B reaction in the whole temperature range.This work provides an independent examination to the current results of the7Be(p,γ)8B reaction.

关键词：反应速率天体物理扭曲波玻恩近似测定中微子通量归一化系数 ANC 对称关系

Simulation of(p,d) reaction on RIBLL2 for study of tensor force

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2015年第4期26卷 72-76页

作者：郭晨雷张高龙屈卫卫 Satoru Terashima Isao Tanihata 乐小云 State Key Laboratory of Software Development Environment Beihang University School of Physics and Nuclear Energy Engineering Beihang University international research center for nuclei and particles in the cosmos Beihang University research center for Nuclear Physics Osaka University

In order to study the effect of tensor force,we plan to perform a(p,d)reaction with a 400–1600 Me V proton beam on the RIBLL2 at Lanzhou.Based on the experimental conditions of RIBLL2,a Monte Carlo method is used to simulate(p,d)reaction process.The distributions of primary beam and scattered deuterons are given on the target and at the F1,F2,F3,and F4 positions.Considering the yield of the deuteron,to separate the produced deuteron from the background particles,the target thickness is optimized.To obtain a clear particle identification spectrum by time of flight(TOF)and energy loss(?E),the distance between the two detectors,as well as the energy and timing resolution of detectors are simulated.As a result,the distance between F2 and F4 is fit for that of TOF.After taking into account the particle distribution at F4,both sizes of Multi-Wire Drift Chamber,namely MWDC2 and MWDC3,are selected to be 50 mm×50 mm.

关键词：反应过程模拟张力 Carlo法能量分辨率实验条件能量损失粒子识别