arXiv: Nuclear Theory最新文献_第10页

Instanton-motivated study of spontaneous fission of odd-A nuclei 奇a核自发裂变的瞬态激发研究

arXiv: Nuclear Theory Pub Date : 2020-07-02 DOI: 10.1103/physrevc.102.054603

W. Brodzi'nski, J. Skalski

{"title":"Instanton-motivated study of spontaneous fission of odd-\u0000A\u0000 nuclei","authors":"W. Brodzi'nski, J. Skalski","doi":"10.1103/physrevc.102.054603","DOIUrl":"https://doi.org/10.1103/physrevc.102.054603","url":null,"abstract":"Using the idea of the instanton approach to quantum tunneling we try to obtain a method of calculating spontaneous fission rates for nuclei with the odd number of neutrons or protons. This problem has its origin in the failure of the adiabatic cranking approximation which serves as the basis in calculations of fission probabilities. Selfconsistent instanton equations, with and without pairing, are reviewed and then simplified to non-selfconsistent versions with phenomenological single-particle potential and seniority pairing interaction. Solutions of instanton-like equations without pairing and actions they produce are studied for the Woods-Saxon potential along realistic fission trajectories. Actions for unpaired particles are combined with cranking actions for even-even cores and fission hindrance for odd-A nuclei is studied in such a hybrid model. With the assumed equal mass parameters for neighbouring odd-A and even-even nuclei, the model shows that freezing the K {pi} configuration leads to a large overestimate of the fission hindrance factors. Actions with adiabatic configurations mostly show not enough hindrance; instanton-like actions for blocked nucleons correct this, but not sufficiently.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75307664","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: 0

Neutron drip line in the deformed relativistic Hartree–Bogoliubov theory in continuum: Oxygen to Calcium 连续体中变形相对论Hartree-Bogoliubov理论中的中子滴线:氧到钙

arXiv: Nuclear Theory Pub Date : 2020-07-02 DOI: 10.1142/S0218301321500099

E. J. In, Youngman Kim, P. Papakonstantinou, Seung-Woo Hong

{"title":"Neutron drip line in the deformed relativistic Hartree–Bogoliubov theory in continuum: Oxygen to Calcium","authors":"E. J. In, Youngman Kim, P. Papakonstantinou, Seung-Woo Hong","doi":"10.1142/S0218301321500099","DOIUrl":"https://doi.org/10.1142/S0218301321500099","url":null,"abstract":"The location of the neutron drip line, currently known for only the lightest elements, remains a fundamental question in nuclear physics. Its description is a challenge for microscopic nuclear energy density functionals, as it must take into account in a realistic way not only the nuclear potential, but also pairing correlations, deformation effects and coupling to the continuum. The recently developed deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) aims to provide a unified description of even-even nuclei throughout the nuclear chart. Here, the DRHBc with the successful density functional PC-PK1 is used to investigate whether and how deformation influences the prediction for the neutron drip-line location for even-even nuclei with 8<=Z<=20, where many isotopes are predicted deformed. The results are compared with those based on the spherical relativistic continuum Hartree-Bogoliubov (RCHB) theory and discussed in terms of shape evolution and the variational principle. It is found that the Ne and Ar drip-line nuclei are different after the deformation effect is included. The direction of the change is not necessarily towards an extended drip line, but rather depends on the evolution of the degree of deformation towards the drip line. Deformation effects as well as pairing and continuum effects treated in a consistent way can affect critically the theoretical description of the neutron drip-line location.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74150153","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

Pion-nucleon scattering to order p4 in SU(3) heavy baryon chiral perturbation theory SU(3)重重子手性微扰理论中的p4阶介子-核子散射

arXiv: Nuclear Theory Pub Date : 2020-07-01 DOI: 10.1103/physrevd.102.116001

Bo Huang

引用次数: 4

Possible octupole deformation of Pb208 and the ultracentral v2 to v3 puzzle Pb208可能的八极变形和超中心v2到v3之谜

arXiv: Nuclear Theory Pub Date : 2020-07-01 DOI: 10.1103/PHYSREVC.102.054905

Patrick Carzon, Skandaprasad Rao, M. Luzum, M. Sievert, J. Noronha-Hostler

{"title":"Possible octupole deformation of \u0000Pb208\u0000 and the ultracentral \u0000v2\u0000 to \u0000v3\u0000 puzzle","authors":"Patrick Carzon, Skandaprasad Rao, M. Luzum, M. Sievert, J. Noronha-Hostler","doi":"10.1103/PHYSREVC.102.054905","DOIUrl":"https://doi.org/10.1103/PHYSREVC.102.054905","url":null,"abstract":"Recent measurements have established the sensitivity of ultracentral heavy-ion collisions to the deformation parameters of non-spherical nuclei. In the case of ${}^{ 129}$Xe collisions, a quadrupole deformation of the nuclear profile led to an enhancement of elliptic flow in the most central collisions. In ${}^{ 208}$Pb collisions a discrepancy exists in similar centralities, where either elliptic flow is over-predicted or triangular flow is under-predicted by hydrodynamic models; this is known as the $v_2$-to-$v_3$ puzzle in ultracentral collisions. Motivated by low-energy nuclear structure calculations, we consider the possibility that $^{208}$Pb nuclei could have a pear shape deformation (octupole), which has the effect of increasing triangular flow in central PbPb collisions. Using the recent data from ALICE and ATLAS, we revisit the $v_2$-to-$v_3$ puzzle in ultracentral collisions, including new constraints from recent measurements of the triangular cumulant ratio $v_3left{4right}/v_3left{2right}$ and comparing two different hydrodynamic models. We find that, while an octupole deformation would slightly improve the ratio between $v_2$ and $v_3$, it is at the expense of a significantly worse triangular flow cumulant ratio. In fact, the latter observable prefers no octupole deformation, with $beta_3lesssim 0.0375$ for ${}^{ 208}$Pb, and is therefore consistent with the expectation for a doubly-magic nucleus even at top collider energies. The $v_2$-to-$v_3$ puzzle remains a challenge for hydrodynamic models.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84911036","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: 7

Accurate bulk properties of nuclei from A=2 to ∞ from potentials with Δ isobars 从具有Δ等压线的电位的A=2到∞的原子核的精确体积性质

arXiv: Nuclear Theory Pub Date : 2020-06-30 DOI: 10.1103/physrevc.102.054301

W. G. Jiang, A. Ekström, C. Forss'en, G. Hagen, G. Jansen, T. Papenbrock

引用次数: 47

Study of freeze-out dynamics of strange hadrons 奇异强子的冻结动力学研究

arXiv: Nuclear Theory Pub Date : 2020-06-30 DOI: 10.1103/PhysRevD.104.034027

S. Singh, P. Ghosh, Jajati k. Nayak

引用次数: 0

Outer crust of a cold, nonaccreting neutron star within the quark-meson-coupling model 夸克-介子耦合模型中一个冷的、非吸积的中子星的外壳

arXiv: Nuclear Theory Pub Date : 2020-06-30 DOI: 10.1103/physrevc.102.065801

Sofija Anti'c, J. Stone, J. Miller, K. Martinez, A. Thomas, P. Guichon

{"title":"Outer crust of a cold, nonaccreting neutron star within the quark-meson-coupling model","authors":"Sofija Anti'c, J. Stone, J. Miller, K. Martinez, A. Thomas, P. Guichon","doi":"10.1103/physrevc.102.065801","DOIUrl":"https://doi.org/10.1103/physrevc.102.065801","url":null,"abstract":"The outer crust properties of cold non-accreting neutron stars are studied within the framework of the quark-meson coupling (QMC) model, which includes the effects of modifications of the quark structure inside individual nucleons when they are within a high-density nuclear medium. With a unique set of five well-constrained adjustable parameters, which have a clear physical basis, the QMC model gives predictions for the ground state observables of even-even nuclei which agree with experiment as well as traditional models. Furthermore, it gives improved theoretical values for nuclei thought to play a role in the outer crusts of neutron stars but for which experimental data is not available. Using the latest experimental data tables wherever possible but otherwise the predictions from the QMC model, we construct an equation of state for the outer crust which is then used within stellar model calculations to obtain an equilibrium sequence of crustal layers, each characterized by a particular neutron rich nuclei. Various properties of the layers are calculated for a range of neutron-star masses, and comparisons are made with alternative equations of state from the literature. This leads to the conclusion that the QMC model successfully predicts the outer crust properties and is fully comparable with the more traditional mass models, which all depend on a larger number of parameters.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88456275","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: 2

Asymptotic characteristics of decay channels of states of light nuclei in the ab initio approach 从头算方法中轻核状态衰减通道的渐近特征

arXiv: Nuclear Theory Pub Date : 2020-06-26 DOI: 10.1103/PHYSREVC.103.024304

D. Rodkin, Yu. M. Tchuvil'sky

引用次数: 0

Shell-model study of calcium isotopes toward their drip line 钙同位素滴注线的壳模型研究

arXiv: Nuclear Theory Pub Date : 2020-06-26 DOI: 10.1103/physrevc.102.054326

L. Coraggio, G. De Gregorio, A. Gargano, N. Itaco, T. Fukui, Y. Z. Ma, F. Xu

引用次数: 5

Global polarization in heavy-ion collisions based on the axial vortical effect 基于轴向涡效应的重离子碰撞全局极化

arXiv: Nuclear Theory Pub Date : 2020-06-25 DOI: 10.1103/physrevc.102.044904

Y. Ivanov

引用次数: 7