Nuclear Theory·nucl-th

Wednesday·December 25, 2019

10 papers—5 primary·5 cross-listed

01
[Submitted on 23 Dec 2019]
Dynamics of one-dimensional correlated nuclear systems within non-equilibrium Green's function theory
Hao Lin · Hossein Mahzoon · Arnau Rios · Pawel Danielewicz
Theory of non-equilibrium Green's function (NGF) provides a practical framework for studying quantum many-body systems out of equilibrium. Extending the previous mean field approach developed for nuclear systems in one dimension with NGF, we introduce isospin degrees of freedom to the Green's functions and incorporate short-range two-body interactions in the second-order self-consistent approximation to correlations, which represents the scattering of momentum orbitals in the Born approximation. We discuss the preparation of a finite nuclear system and examine the impact of correlations on the ground state. We also excite a finite symmetric nuclear system to oscillate in an isovector dipole mode and explore the dissipation effects in the oscillation. Finally, we demonstrate how to boost a slab to a constant and stable motion in a box, based on Galilean covariance of the theory. The studies in this paper lay the ground for the future exploration of collisions of correlated nuclear systems in one dimension.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1912.11069 [pdf]
Annals Phys.(2020)·5 citations
02
[Submitted on 23 Dec 2019]
Covariant Density Functional Theory in Nuclear Physics and Astrophysics
Junjie Yang🇺🇸 · J. Piekarewicz🇺🇸
How does subatomic matter organize itself? Neutron stars are cosmic laboratories uniquely poised to answer this fundamental question that lies at the heart of nuclear science. Newly commissioned rare isotope facilities, telescopes operating across the entire electromagnetic spectrum, and ever more sensitive gravitational wave detectors will probe the properties of neutron-rich matter with unprecedented precision over an enormous range of densities. Yet, a coordinated effort between observation, experiment, and theoretical research is of paramount importance for realizing the full potential of these investments. Theoretical nuclear physics provides valuable insights into the properties of neutron-rich matter in regimes that are not presently accessible to experiment or observation. In particular, nuclear density functional theory is likely the only tractable framework that can bridge the entire nuclear landscape by connecting finite nuclei to neutron stars. This compelling connection is the main scope of the present review.
Comments:
23 pages, 5 figures. When citing this paper, please use the following: Yang J, Piekarewicz J. Covariant Density Functional Theory in Nuclear Physics and Astrophysics. Annual Review of Nuclear and Particle Science Volume 70: Submitted. DOI: 10.1146/annurev-nucl-101918-023608
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Experiment (nucl-ex)
arXiv:
1912.11112 [pdf]
Ann.Rev.Nucl.Part.Sci.(2020)·41 citations
03
[Submitted on 23 Dec 2019]
Empirical constraints on the high-density equation of state from multi-messenger observables
Márcio Ferreira🇵🇹 · M. Fortin🇵🇱 · Tuhin Malik🇮🇳 · B. K. Agrawal🇮🇳 · Constança Providência🇵🇹
We search for possible correlations between neutron star observables and thermodynamic quantities that characterize high density nuclear matter. We generate a set of model-independent equations of state describing stellar matter from a Taylor expansion around saturation density. Each equation of state which is a functional of the nuclear matter parameters is thermodynamically consistent, causal and compatible with astrophysical observations. We find that the neutron star tidal deformability and radius are strongly correlated with the pressure, the energy density and the sound velocity at different densities. Similar correlations are also exhibited by a large set of mean-field models based on non-relativistic and relativistic nuclear energy density functionals. These model independent correlations can be employed to constrain the equation of state at different densities above saturation from measurements of NS properties with multi-messenger observations. In particular, precise constraints on the radius of PSR J0030+0451 thanks to NICER observations would allow to better infer the properties of matter around two times the nuclear saturation density.
Comments:
10 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
1912.11131 [pdf]
PRD(2020)·29 citations
04
[Submitted on 23 Dec 2019]
Role of residual interaction in the relativistic description of M1 excitation
Tomohiro Oishi · Goran Kruzic · Nils Paar
Magnetic dipole (M1) excitation is the leading mode of multi-nucleon excitations induced by the magnetic field, and is a phenomenon of the spin-orbit (SO) splitting and residual interactions involved. In this work, we investigate the effects of the residual interactions on the M1 excitation from a novel perspective, the framework of relativistic nuclear energy-density functional (RNEDF). The relativistic Hartree-Bogoliubov (RHB) model is utilized to determine the nuclear ground state properties, while the relativistic quasi-particle random-phase approximation (RQRPA) is employed for the description of M1-excitation properties. From the analysis of M1 mode in the Ca isotope chain, role of the isovector-pseudovector (IV-PV) residual interaction is discussed. For open-shell nuclei, the pairing correlation also plays a noticeable role in the M1 mode. The experimental data on M1 mode is expected to provide a suitable reference to improve and optimize the theoretical aspects to describe the residual interactions.
Comments:
22 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1912.11147 [pdf]
J.Phys.G(2020)·13 citations
05
[Submitted on 24 Dec 2019]
Impact of statistical uncertainties on the composition of the outer crust of a neutron star
A. Pastore🇬🇧 · D. Neill🇬🇧 · H. Powell🇬🇧 · K. Medler🇬🇧 · C. Barton🇬🇧
By means of Monte Carlo methods, we perform a full error analysis on the Duflo-Zucker mass model. In particular, we study the presence of correlations in the residuals to obtain a more realistic estimate of the error bars on the predicted binding energies. To further reduce the discrepancies between model prediction and experimental data we also apply a Multilayer Perceptron Neural Network. We show that the root mean square of the model further reduces of roughly 40\%. We then use the resulting models to predict the composition of the outer crust of a non accreting neutron star. We provide a first estimate of the impact of error propagation on the resulting equation of state of the system.
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
1912.11365 [pdf]
PRC(2020)·25 citations
06
[Submitted on 23 Dec 2019] (cross-list from hep-ph)
Three Point Energy Correlators in the Collinear Limit: Symmetries, Dualities and Analytic Results
Hao Chen🇨🇳 · Ming-Xing Luo🇨🇳 · Ian Moult🇺🇸 · Tong-Zhi Yang🇨🇳 · Xiaoyuan Zhang🇨🇳 · Hua Xing Zhu🇨🇳
Energy Correlators measure the energy deposited in multiple detectors as a function of the angles between the detectors. In this paper, we analytically compute the three particle correlator in the collinear limit in QCD for quark and gluon jets, and also in $N = 4$ super Yang-Mills theory. We find an intriguing duality between the integrals for the energy correlators and infrared finite Feynman parameter integrals, which maps the angles of the correlators to dual momentum variables. In $N = 4$ , we use this duality to express our result as a rational sum of simple Feynman integrals (triangles and boxes). In QCD our result is expressed as a sum of the same transcendental functions, but with more complicated rational functions of cross ratio variables as coefficients. Our results represent the first analytic calculation of a three-prong jet substructure observable of phenomenological relevance for the LHC, revealing unexplored simplicity in the energy flow of QCD jets. They also provide valuable data for improving the understanding of the light-ray operator product expansion.
Comments:
52 pages, 12 figures v2. Minor typos corrected, matches journal version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
1912.11050 [pdf]
JHEP(2020)·116 citations
07
[Submitted on 24 Dec 2019] (cross-list from hep-ph)
Reanalysis of the most strange dibaryon within constituent quark models
Hongxia Huang🇨🇳 · Xinmei Zhu🇨🇳 · Jialun Ping🇨🇳
The most strange dibaryon $ΩΩ$ with quantum numbers $S = - 6$ , $I = 0$ , and $J^{P} = 0^{+}, 1^{-}, 2^{+}, 3^{-}$ is reanalyzed in the framework of quark delocalization color screening model (QDCSM) and chiral quark model (ChQM). The $ΩΩ$ dibaryon with $J^{P} = 0^{+}$ is bound, and the one with other quantum numbers $J^{P} = 1^{-}, 2^{+}, 3^{-}$ are all unbound in our calculation. The low-energy scattering phase shifts, the scattering length, and the effective range of the $ΩΩ$ dibaryon with $J^{P} = 0^{+}$ also support the existence of such strange dibaryon. This dibaryon is showed to be a shallow bound state in QDCSM, while the binding energy becomes much larger in the ChQM by including the effect of the hidden-color channel coupling. And the scalar nonet meson-exchange in the ChQM also provides more attraction for the $ΩΩ$ system. Experimental search for such most strange dibaryon will provide much information for understanding the hadron-hadron interactions in different quark models.
Comments:
8 pages, 3 figures. arXiv admin note: text overlap with arXiv:1507.07124
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1912.11256 [pdf]
PRC(2020)·10 citations
08
[Submitted on 24 Dec 2019] (cross-list from hep-th)
Magneto-vortical effect in strongly coupled plasma
Yanyan Bu🇨🇳 · Shu Lin🇨🇳
Based on a holographic model incorporating both chiral anomaly and gravitational anomaly, we study the effect of magneto-vortical coupling on transport properties of a strongly coupled plasma. The focus of present work is on the generation of a vector charge density and an axial current, as response to vorticity in a magnetized plasma. The transport coefficients parameterising the vector charge density and axial current are calculated both analytically (in the weak magnetic field limit) and also numerically (for general values of the magnetic field). We find the generation of vector charge receives both non-anomalous and anomalous contributions, with the non-anomalous contribution dominating in the limit of strong magnetic field and the anomalous contribution sensitive to both chiral anomaly and gravitational anomaly. On the contrary, we find the axial current is induced entirely due to the gravitational anomaly, thus we interpret the axial current generation as chiral vortical effect. The corresponding chiral vortical conductivity is found to be suppressed by the magnetic field. By Onsager relation, these transport coefficients are responsible for the generation of a thermal current due to a transverse electric field or a transverse axial magnetic field, which we call thermal Hall effect and thermal axial magnetic effect, respectively.
Comments:
37 pages, 6 figures
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1912.11277 [pdf]
EPJC(2020)·10 citations
09
[Submitted on 24 Dec 2019] (cross-list from hep-ph)
Diffractive Dissociation of Alpha Particles as a Test of Isophobic Short-Range Correlations inside Nuclei
Jennifer Rittenhouse West🇺🇸 · Stanley J. Brodsky🇺🇸 · Guy F. de Téramond🇨🇷 · Iván Schmidt🇨🇱
The CLAS collaboration at Jefferson Laboratory has compared nuclear parton distributions for a range of nuclear targets and found that the EMC effect measured in deep inelastic lepton-nucleus scattering has a strongly "isophobic" nature. This surprising observation suggests short-range correlations between neighboring $n$ and $p$ nucleons in nuclear wavefunctions that are much stronger compared to $p - p$ or $n - n$ correlations. In this paper we propose a definitive experimental test of the nucleon-nucleon explanation of the isophobic nature of the EMC effect: the diffractive dissociation on a nuclear target $A$ of high energy $^{4} He$ nuclei to pairs of nucleons $n$ and $p$ with high relative transverse momentum, $α + A \to n + p + A^{'} + X$ . The comparison of $n - p$ events with $p - p$ and $n - n$ events directly tests the postulated breaking of isospin symmetry. The experiment also tests alternative QCD-level explanations for the isophobic EMC effect. In particular it will test a proposal for hidden-color degrees of freedom in nuclear wavefunctions based on isospin-zero $[u d]$ diquarks.
Comments:
5 pages, references added, clarifications due to helpful referee comments (latexdiff for all changes). Accepted for publication in Physics Letters B
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1912.11288 [pdf]
PLB(2020)·8 citations
10
[Submitted on 20 Dec 2019] (cross-list from nucl-ex)
N $^{*}$ Experiments and what they tell us about Strong QCD Physics
Volker D. Burkert🇺🇸
I give an overview on experimental studies of the spectrum and the structure of the excited states of the nucleon and what we can learn about their internal structure. One focus is on the efforts to obtain a more complete picture of the light-quark baryon excitation spectrum employing electromagnetic beams that will allow us to draw some conclusions on the symmetries underlying the spectrum. For the higher mass excitations, the full employment of coupled channel approaches is essential when searching for new excited states in the large amounts of data already accumulated in different channels involving a variety of polarization observables. The other focus is on the study of transition form factors and helicity amplitudes and their dependences on $Q^{2}$ , especially on some of the more prominent resonances, especially $Δ (1232) \frac{3}{2}^{+}$ , $N (1440) \frac{1}{2}^{+}$ , and negative parity states $N (1535) \frac{1}{2}^{-}$ , and $N (1675) \frac{5}{2}^{-}$ . These were obtained in pion and eta electroproduction experiments off proton targets and have already led to further insights in the active degrees-of-freedom as a function of the distance scale involved.
Comments:
12 Pages, 18 figures. Invited talk given at the N*2019 conference at Bonn, Germany. arXiv admin note: text overlap with arXiv:1603.00919, arXiv:1801.10480
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1912.11400 [pdf]
EPJ Web Conf.(2020)·21 citations

Affiliations

first authorsco-authorsvia INSPIRE