arXiv: Nuclear Theory最新文献_第7页

The mean square radius of the neutron distribution and the skin thickness derived from electron scattering 由电子散射得到的中子分布的均方半径和趋肤厚度

arXiv: Nuclear Theory Pub Date : 2020-09-02 DOI: 10.1093/ptep/ptaa177

H. Kurasawa, T. Suda, Toshio Suzuki

引用次数: 3

A study of nuclear radii and neutron skin thickness of neutron-rich nuclei near the neutron drip line 中子滴线附近富中子核半径和中子皮厚的研究

arXiv: Nuclear Theory Pub Date : 2020-09-01 DOI: 10.1142/S0218301320500767

U. Rahaman, M. Ikram, M. Imran, A. A. Usmani

引用次数: 0

State densities of heavy nuclei in the static-path plus random-phase approximation 静态路径加随机相位近似中重核的态密度

arXiv: Nuclear Theory Pub Date : 2020-08-31 DOI: 10.1103/PhysRevC.103.064310

P. Fanto, Y. Alhassid

{"title":"State densities of heavy nuclei in the static-path plus random-phase approximation","authors":"P. Fanto, Y. Alhassid","doi":"10.1103/PhysRevC.103.064310","DOIUrl":"https://doi.org/10.1103/PhysRevC.103.064310","url":null,"abstract":"Nuclear state densities are important inputs to statistical models of compound-nucleus reactions. State densities are often calculated with self-consistent mean-field approximations that do not include important correlations and have to be augmented with empirical collective enhancement factors. Here, we benchmark the static-path plus random-phase approximation (SPA+RPA) to the state density in a chain of samarium isotopes $^{148-155}$Sm against exact results (up to statistical errors) obtained with the shell model Monte Carlo (SMMC) method. The SPA+RPA method incorporates all static fluctuations beyond the mean field together with small-amplitude quantal fluctuations around each static fluctuation. Using a pairing plus quadrupole interaction, we show that the SPA+RPA state densities agree well with the exact SMMC densities for both the even- and odd-mass isotopes. For the even-mass isotopes, we also compare our results with mean-field state densities calculated with the finite-temperature Hartree-Fock-Bogoliubov (HFB) approximation. We find that the SPA+RPA repairs the deficiencies of the mean-field approximation associated with broken rotational symmetry in deformed nuclei and the violation of particle-number conservation in the pairing condensate. In particular, in deformed nuclei the SPA+RPA reproduces the rotational enhancement of the state density relative to the mean-field state density.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73345320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Microscopic model for the collective enhancement of nuclear level densities 核能级密度集体增强的微观模型

arXiv: Nuclear Theory Pub Date : 2020-08-22 DOI: 10.1103/physrevc.102.054606

Jie-Cheng Zhao, T. Nikšić, D. Vretenar

{"title":"Microscopic model for the collective enhancement of nuclear level densities","authors":"Jie-Cheng Zhao, T. Nikšić, D. Vretenar","doi":"10.1103/physrevc.102.054606","DOIUrl":"https://doi.org/10.1103/physrevc.102.054606","url":null,"abstract":"A microscopic method for calculating nuclear level densities (NLD) is developed, based on the framework of energy density functionals. Intrinsic level densities are computed from single-quasiparticle spectra obtained in a finite-temperature self-consistent mean-field (SCMF) calculation that takes into account nuclear deformation, and is specified by the choice of the energy density functional (EDF) and pairing interaction. The total level density is calculated by convoluting the intrinsic density with the corresponding collective level density, determined by the eigenstates of a five-dimensional quadrupole or quadrupole plus octupole collective Hamiltonian. The parameters of the Hamiltonian (inertia parameters, collective potential) are consistently determined by deformation-constrained SCMF calculations using the same EDF and pairing interaction. The model is applied in the calculation of NLD of $^{94,96,98}$Mo, $^{106,108}$Pd, $^{106,112}$Cd, $^{160,162,164}$Dy, $^{166}$Er, and $^{170,172}$Yb, in comparison with available data. It is shown that the collective enhancement of the intrinsic level density, consistently computed from the eigenstates of the corresponding collective Hamiltonian, leads to total NLDs that are in excellent agreement with data over the whole energy range of measured values.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79285555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Microscopic description of quadrupole-octupole coupling in actinides with the Gogny-D1M energy density functional 用Gogny-D1M能量密度泛函描述锕系元素中四极-八极耦合的微观描述

arXiv: Nuclear Theory Pub Date : 2020-08-21 DOI: 10.1088/1361-6471/abb000

R. Rodríguez-Guzmán, Y. Humadi, L. Robledo

引用次数: 10

Gluonic hot spot initial conditions in heavy-ion collisions 重离子碰撞中的胶子热点初始条件

arXiv: Nuclear Theory Pub Date : 2020-08-20 DOI: 10.1103/PHYSREVC.103.024906

R. Snyder, M. Byres, S. Lim, J. Nagle

引用次数: 3

Charge conservation and higher moments of charge fluctuations 电荷守恒和更高的电荷波动矩

arXiv: Nuclear Theory Pub Date : 2020-08-19 DOI: 10.1103/physrevc.102.064906

S. Pratt, R. Steinhorst

{"title":"Charge conservation and higher moments of charge fluctuations","authors":"S. Pratt, R. Steinhorst","doi":"10.1103/physrevc.102.064906","DOIUrl":"https://doi.org/10.1103/physrevc.102.064906","url":null,"abstract":"Higher moments of distributions of net charge and baryon number in heavy-ion collisions have been proposed as signals of fundamental QCD phase transitions. In order to better understand background processes for these observables, models are presented which enable one to gauge the effects of local charge conservation, decays of resonances and clusters, Bose symmetrization, and volume fluctuations. Monte Carlo methods for generating samplings of particles consistent with local charge conservation are presented, and are followed by a review of simple analytic models involving a single type of charge with a constant experimental efficiency. The main model consists of thermal emission superimposed onto a simple parameterization of collective flow, known as a blast-wave, with emission being consistent with individual canonical ensembles. The spatial extent of local charge conservation is parameterized by the size and extent over which charge is conserved. The sensitivity of third and fourth order moments, skewness and kurtosis, to these parameters, and to beam energy and baryon density is explored. Comparisons with STAR data show that a significant part of the observed non-Poissonian fluctuations in net-proton fluctuations are explained by charge and baryon-number conservation, but that measurements of the STAR collaboration for fluctuations of net electric charge significantly differ from expectations of the models presented here.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77941506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Relativistic Kelvin circulation theorem for ideal Magnetohydrodynamics 理想磁流体力学的相对论开尔文循环定理

arXiv: Nuclear Theory Pub Date : 2020-08-18 DOI: 10.11804/NuclPhysRev.37.2019CNPC19

Jianfei Wang, Shi Pu

引用次数: 0

Improvements to the macroscopic-microscopic approach of nuclear fission 核裂变宏观-微观方法的改进

arXiv: Nuclear Theory Pub Date : 2020-08-15 DOI: 10.1103/PHYSREVC.103.034617

M. Verriere, M. Mumpower

{"title":"Improvements to the macroscopic-microscopic approach of nuclear fission","authors":"M. Verriere, M. Mumpower","doi":"10.1103/PHYSREVC.103.034617","DOIUrl":"https://doi.org/10.1103/PHYSREVC.103.034617","url":null,"abstract":"The well established macroscopic-microscopic (mac-mic) description of nuclear fission enables the prediction of fission fragment yields for a broad range of fissioning systems. In this work, we present several key enhancements to this approach. We improve upon the microscopic sector of nuclear potential energy surfaces by magnifying the Lipkin-Nogami equations' resolution and strengthening the Strutinsky procedure, thus reducing spurious effects from the continuum. We further present a novel deterministic method for calculating fission dynamics under the assumption of strongly damped nucleonic motion. Our technique utilizes the memoryless property of Markov Chains to produce fission yields that do not rely on the statistical accumulation of scission events. We show that our new technique is equivalent to the Metropolis random-walk pioneered over the past decade by Randrup and colleagues. It further improves upon it, as we remove the need for altering the nuclear landscape via a biased potential. With our final improvement, we calculate scission configurations using particle number projection, which affords the simultaneous calculation of both mass and charge yield distributions. Fission fragments are thus calculated from the quantum mechanical $A$-body states of the potential energy surface rather than the collective mass asymmetry variable ($alpha_{rm g}$) of the Finite-Range Liquid-Drop Model (FRLDM) used in past work. We highlight the success of our enhancements by predicting the odd-even staggering and the charge polarization for the neutron-induced fission of ${}^{233}$U and ${}^{235}$U.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79417468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Discovery versus precision in nuclear physics: A tale of three scales 核物理中的发现与精确:三个尺度的故事

arXiv: Nuclear Theory Pub Date : 2020-08-14 DOI: 10.1103/physrevc.102.055206

G. Miller

引用次数: 4