arXiv: Nuclear Theory最新文献_第4页

Investigation of $$varXi ^- nn$$ ($$S=-2$$) hypernucleus in low-energy pionless halo effective theory 低能无针晕有效理论中$$varXi ^- nn$$ ($$S=-2$$)超核的研究

arXiv: Nuclear Theory Pub Date : 2020-10-23 DOI: 10.1140/EPJS/S11734-021-00007-1

Ghanashyam Meher, U. Raha

引用次数: 1

Dyson–Schwinger approach to pion–nucleon scattering using time-ordered perturbation theory 用时间序微扰理论研究介子-核子散射的Dyson-Schwinger方法

arXiv: Nuclear Theory Pub Date : 2020-10-22 DOI: 10.1063/5.0034753

B. Blankleider, J. Wray, A. Kvinikhidze

引用次数: 0

Total reaction cross section on a deuteron target and the eclipse effect of the constituent neutron and proton 氘核靶上的总反应截面及组成中子和质子的蚀效应

arXiv: Nuclear Theory Pub Date : 2020-10-20 DOI: 10.1103/physrevc.102.054601

W. Horiuchi, Y. Suzuki, T. Uesaka, M. Miwa

{"title":"Total reaction cross section on a deuteron target and the eclipse effect of the constituent neutron and proton","authors":"W. Horiuchi, Y. Suzuki, T. Uesaka, M. Miwa","doi":"10.1103/physrevc.102.054601","DOIUrl":"https://doi.org/10.1103/physrevc.102.054601","url":null,"abstract":"Background: Eclipse effect of the neutron and proton in a deuteron target is essential to correctly describe high-energy deuteron scattering. The nucleus-deuteron scattering needs information not only on the nucleus-proton but also the nucleus-neutron interaction, for which no direct measurement of the nucleus-neutron cross sections is available for unstable nuclei. \u0000Purpose: We systematically evaluated the total reaction cross sections by a deuteron target to explore the feasibility of extracting the nucleus-neutron interaction from measurable cross sections. \u0000Methods: High-energy nucleus-deuteron collision is described by the Glauber model, in which the proton and neutron configuration of the deuteron is explicitly taken into account. \u0000Results: Our calculation reproduces available experimental total reaction cross section data on the nucleus-deuteron scattering. The possibility of extracting the nucleus-neutron total reaction cross section from nucleus-deuteron and nucleus-proton total reaction cross sections is explored. The total reaction cross sections of a nucleus by proton, neutron, and deuteron targets can be expressed, to good accuracy, in terms of the nuclear matter radius and neutron skin thickness. Incident-energy dependence of the total reaction cross sections is examined. \u0000Conclusions: The total reaction cross section on a deuteron target includes information on both the nucleus-neutron and nucleus-proton profile functions. Measuring the cross sections by deuteron and proton targets is a promising tool to extract the nuclear size properties.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83262261","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

Windowed multipole representation of R-matrix cross sections r矩阵截面的窗口多极表示

arXiv: Nuclear Theory Pub Date : 2020-10-20 DOI: 10.1103/PhysRevC.103.064610

P. Ducru, A. Alhajri, I. Meyer, B. Forget, V. Sobes, C. Josey, Jin'gang Liang

{"title":"Windowed multipole representation of \u0000R\u0000-matrix cross sections","authors":"P. Ducru, A. Alhajri, I. Meyer, B. Forget, V. Sobes, C. Josey, Jin'gang Liang","doi":"10.1103/PhysRevC.103.064610","DOIUrl":"https://doi.org/10.1103/PhysRevC.103.064610","url":null,"abstract":"Nuclear cross sections are basic inputs to any nuclear computation. Campaigns of experiments are fitted with the parametric R-matrix model of quantum nuclear interactions, and the resulting cross sections are documented - both point-wise and as resonance parameters (with uncertainties) - in standard evaluated nuclear data libraries (ENDF, JEFF, BROND, JENDL, CENDL, TENDL): these constitute our common knowledge of fundamental nuclear physics. In the past decade, a collaborative effort has been deployed to establish a new nuclear cross section library format - the Windowed Multipole Library - with the goal of considerably reducing the cost of cross section calculations in nuclear transport simulations. This article lays the theoretical foundations underpinning these efforts. From general R-matrix scattering theory, we derive the windowed multipole representation of nuclear cross sections. Though physically and mathematically equivalent, the windowed multipole representation is particularly well suited for subsequent temperature treatment of angle-integrated cross sections: we show that accurate Doppler broadening can be performed analytically up to the first reaction threshold; and we derive cross sections temperature derivatives to any order. Furthermore, we here establish a way of converting the R-matrix resonance parameters uncertainty (covariance matrices) into windowed multipole parameters uncertainty. We show that generating stochastic nuclear cross sections by sampling from the resulting windowed multipole covariance matrix can reproduce the cross section uncertainty in the original nuclear data file. Through this foundational article, we hope to make the Windowed Multipole Representation accessible, reproducible, and usable for the nuclear physics community, as well as provide the theoretical basis for future research on expanding its capabilities.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76248103","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: 4

Future Physics Perspectives on the Equation of State from Heavy Ion Collisions to Neutron Stars 从重离子碰撞到中子星状态方程的未来物理学展望

arXiv: Nuclear Theory Pub Date : 2020-10-17 DOI: 10.1088/1361-6471/abe104

V. Dexheimer, J. Noronha, J. Noronha-Hostler, N. Yunes, C. Ratti

引用次数: 33

Microscopic coupled-channel calculation of proton and alpha inelastic scattering to the $4^+_1$ and $4^+_2$ states of $^{24}textrm{Mg}$ $^{24}textrm{Mg}$ $4^+_1$和$4^+_2$态质子和α非弹性散射的微观耦合通道计算

arXiv: Nuclear Theory Pub Date : 2020-10-16 DOI: 10.1093/PTEP/PTAB029

Y. Kanada-En’yo, K. Ogata

{"title":"Microscopic coupled-channel calculation of proton and alpha inelastic scattering to the $4^+_1$ and $4^+_2$ states of $^{24}textrm{Mg}$","authors":"Y. Kanada-En’yo, K. Ogata","doi":"10.1093/PTEP/PTAB029","DOIUrl":"https://doi.org/10.1093/PTEP/PTAB029","url":null,"abstract":"Background: The triaxial and hexadecapole deformations of the K=0+ and K=2+ bands of 24Mg have been investigated by the inelastic scatterings of various probes, including electrons, protons, and alpha particles, for a prolonged time. However, it has been challenging to explain the unique properties of the scatterings observed for the $4^+_1$ state through reaction calculations. Purpose: To investigate the structure and transition properties of the K=0+ and K=2+ bands of 24Mg employing the microscopic structure and reaction calculations via inelastic proton and alpha-scattering. Particularly, the E4 transitions to the $4^+_1$ and $4^+_2$ states were reexamined. Method: The structure of 24Mg was calculated employing the variation after the parity and total-angular momentum projections in the framework of the antisymmetrized molecular dynamics(AMD). The inelastic proton and alpha reactions were calculated by the microscopic coupled-channel (MCC) approach by folding the Melbourne g-matrix NN interaction with the AMD densities of 24Mg. Results: Reasonable results were obtained on the properties of the structure, including the energy spectra and E2 and E4 transitions of the K=0+ and K=2+ bands owing to the enhanced collectivity of triaxial deformation. The MCC+AMD calculation successfully reproduced the angular distributions of the $4^+_1$ and $4^+_2$ cross sections of proton scattering at incident energies of $E_p$=40--100MeV and alpha-scattering at $E_alpha$=100--400MeV. Conclusions: This is the first microscopic calculation that described the unique properties of the $0^+_1to 4^+_1$ transition. In the inelastic scattering to the $4^+_1$ state, the dominant two-step process of the $0^+_1to 2^+_1to 4^+_1$ transitions and the deconstructive interference is the weak one-step process were essential.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74625560","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

Mirror energy differences in T=1/2f7/2-shell nuclei within isospin-dependent density functional theory 同位旋依赖密度泛函理论中T=1/2f7/2壳核的镜像能差

arXiv: Nuclear Theory Pub Date : 2020-10-13 DOI: 10.1103/PhysRevC.103.054320

P. Bączyk, W. Satula

{"title":"Mirror energy differences in \u0000T=1/2f7/2\u0000-shell nuclei within isospin-dependent density functional theory","authors":"P. Bączyk, W. Satula","doi":"10.1103/PhysRevC.103.054320","DOIUrl":"https://doi.org/10.1103/PhysRevC.103.054320","url":null,"abstract":"Background: Small asymmetry between neutrons and protons, caused by the differences in masses and charges of the up and down constituent quarks leads to the isospin symmetry breaking. The isospin non-conservation affects broad range of observables from superallowed Fermi weak interaction to isospin-forbidden electromagnetic rates. Its most profound and cleanest manifestation are systematic shifts in masses and excitation energies of mirror atomic nuclei. \u0000Purpose: Recently, we constructed the charge-dependent DFT that includes class II and III local interactions and demonstrated that the model allows for very accurate reproduction of Mirror and Triplet Displacement energies in a very broad range of masses. The aim of this work is to further test the charge-dependent functional by studying Mirror Energy Differences (MEDs) in function of angular momentum $I$. \u0000Methods: To compute MEDs we use DFT-rooted no core configuration interaction model. This post mean-field method restores rotational symmetry and takes into account configuration mixing within a space that includes relevant (multi)particle-(multi)hole Slater determinants. \u0000Results: We applied the model to $f_{7/2}$-shell mirror pairs of $A=43$, $45$, $47$, and $49$ focusing on MEDs in low-spin part (below band crossing) what allowed us to limit the model space to seniority one and three (one broken pair) configurations. \u0000Conclusions: We demonstrate that, for spins $Ileq 15/2$ being subject of the present study, our model reproduces well experimental MEDs which vary strongly in function of $I$ and $A$. The quality of model's predictions is comparable to the nuclear shell-model results by Bentley et al. Phys. Rev. C 92, 024310 (2015).","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84347087","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

Effective-field-theory analysis of boson-trimer bond lengths to next-to-leading order 玻色子三聚体键长至次领先阶的有效场论分析

arXiv: Nuclear Theory Pub Date : 2020-10-13 DOI: 10.1103/PHYSREVA.103.023333

J. Qin, Jared Vanasse

引用次数: 2

Effect of the crust on neutron star empirical relations 地壳对中子星经验关系的影响

arXiv: Nuclear Theory Pub Date : 2020-10-12 DOI: 10.1103/physrevd.102.103003

Márcio Ferreira, C. Providencia

{"title":"Effect of the crust on neutron star empirical relations","authors":"Márcio Ferreira, C. Providencia","doi":"10.1103/physrevd.102.103003","DOIUrl":"https://doi.org/10.1103/physrevd.102.103003","url":null,"abstract":"We analyze how the crust equation of state affects several neutron star properties and how it impacts on possible constraints inferred from astrophysical observations. Using three distinct crusts, we generate three sets of model-independent equations of state describing stellar matter from a Taylor expansion around saturation density. The equations of state are thermodynamically consistent, causal, and compatible with astrophysical observations. The relations between the tidal deformability $Lambda$ and compactness $C$, Love number $k_2$ and radius of neutron star with mass $M$ are studied, and the effect of the crust equation of state on these relations analyzed. In most of the relations, the impact of the crust equation of state is not larger that 2%. If, however, a fixed neutron star mass is considered, the relation between the tidal deformability and the radius depends on the crust. We have found that the relation $Lambda_{M_i} = alpha R_{M_i}^{beta}$ becomes almost exact and crust independent for massive neutron stars. It is shown that it is possible to determine the tidal deformability of an 1.4$M_odot$ star from the GW179817 effective tidal deformability $tildeLambda$ with an accuracy of at least $approx 10%$. A high correlation between $tildeLambda$ and the radius of the most massive star of the neutron star binary was confirmed, however, it was demonstrated that the crust has an effect of $approx 14%$ on this relation. We have found that the relation $Lambda_1/Lambda_2=q^a$ depends on $M_{text{chirp}}$ as $asim sqrt{M_{text{chirp}}}$.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81738960","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

Electroweak decay of quark matter within dense astrophysical combustion flames 稠密天体物理燃烧火焰中夸克物质的电弱衰变

arXiv: Nuclear Theory Pub Date : 2020-10-10 DOI: 10.1103/PhysRevC.103.055816

J. A. Rosero-Gil, G. Lugones

{"title":"Electroweak decay of quark matter within dense astrophysical combustion flames","authors":"J. A. Rosero-Gil, G. Lugones","doi":"10.1103/PhysRevC.103.055816","DOIUrl":"https://doi.org/10.1103/PhysRevC.103.055816","url":null,"abstract":"We study the weak interaction processes taking place within a combustion flame that converts dense hadronic matter into quark matter in a compact star. Using the Boltzmann equation we follow the evolution of a small element of just deconfined quark matter all along the flame interior until it reaches chemical equilibrium at the back boundary of the flame. We obtain the reaction rates and neutrino emissivities of all the relevant weak interaction processes without making any assumption about the neutrino degeneracy. We analyse systematically the role the initial conditions of unburnt hadronic matter, such as density, temperature, neutrino trapping and composition, focusing on typical astrophysical scenarios such as cold neutron stars, protoneutron stars, and post merger compact objects. We find that the temperature within the flame rises significantly in a timescale of 1 nanosecond. The increase in $T$ strongly depends on the initial strangeness of hadronic matter and tends to be more drastic at larger densities. Typical final values range between $20$ and $60 , mathrm{MeV}$. The nonleptonic process $u + d rightarrow u + s$ is always dominant in cold stars, but in hot object the process $u + e^{-} leftrightarrow d + {nu_e}$ becomes relevant, and in some cases dominant, near chemical equilibrium. The rates for the other processes are orders of magnitude smaller. We find that the neutrino emissivity per baryon is very large, leading to a total energy release per baryon of $2-64 , mathrm{MeV}$ in the form of neutrinos along the flame. We discuss some astrophysical consequences of the results.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77241434","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