Nuclear Theory·nucl-th

Friday·March 18, 2022

8 papers—3 primary·5 cross-listed

01
[Submitted on 17 Mar 2022]
Neutron star mass formula with nuclear saturation parameters
Hajime Sotani · Hajime Togashi
We derive the empirical formulas for the neutron star mass and gravitational redshift as a function of the central density and specific combination of the nuclear saturation parameters, which are applicable to the stellar models constructed with the central density up to threefold nuclear saturation density. Combining the both empirical formulas, one also estimates the neutron star radius. In practice, we find that the neutron star mass (radius) can be estimated within $\sim 10%$ (a few percent) accuracy by comparing the mass and radius evaluated with our empirical formulas to those determined with the specific equation of state. Since our empirical formulas directly connect the neutron star mass and radius to the nuclear saturation parameters, one can discuss the neutron star properties with the specific values of nuclear saturation parameters constrained via nuclear experiments.
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2203.09004 [pdf]
PRD(2022)·9 citations
02
[Submitted on 17 Mar 2022]
Core structures of vortices in Ginzburg-Landau theory for neutron $^{3} P_{2}$ superfluids
Michikazu Kobayashi🇯🇵 · Muneto Nitta🇯🇵
We investigate vortex solutions in the Ginzburg-Landau theory for neutron $^{3} P_{2}$ superfluids relevant for neutron star cores in which neutron pairs possess the total angular momentum $J = 2$ with spin-triplet and $P$ wave, in the presence of the magnetic field parallel to the angular momentum of vortices. The ground state is known to be in the uniaxial nematic (UN) phase in the absence of magnetic field, while it is in the $D_{2}$ ( $D_{4}$ ) biaxial nematic (BN) phase in the presence of the magnetic field below (above) the critical value. We find that a singly quantized vortex always splits into two half-quantized non-Abelian vortices connected by soliton(s) as a vortex molecule with any strength of the magnetic field. In the UN phase, two half-quantized vortices with ferromagnetic cores are connected by a linear soliton with the $D_{4}$ BN order. In the $D_{2}$ ( $D_{4}$ ) BN phase, two half-quantized vortices with cyclic cores are connected by three linear solitons with the $D_{4}$ ( $D_{2}$ ) BN order. The energy of the vortex molecule monotonically increases and the distance between the two half-quantized vortices decreases with the magnetic field increases, except for a discontinuously increasing jump of the distance at the critical magnetic field. We also construct an isolated half-quantized non-Abelian vortex in the $D_{4}$ BN phase.
Comments:
13 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); Quantum Gases (cond-mat.quant-gas)
arXiv:
2203.09300 [pdf]
PRC(2022)·12 citations
03
[Submitted on 17 Mar 2022]
Study on nuclear $α$ -decay energy by an artificial neural network with pairing and shell effects
Hong-Qiang You · Zheng-Zhe Qu · Ren-Hang Wu · Hao-Ze Su · Xiao-Tao He
We build and train the artificial neural network model (ANN) based on the experimental $α$ -decay energy ( $Q_{α}$ ) data. Besides decays between the ground states of parent and daughter nuclei, decays from the ground state of parent nuclei to the excited state of daughter nuclei are also included. By this way, the number of samples are increased dramatically. The results calculated by ANN model reproduce the experimental data with a good accuracy. The root-mean-square (rms) relative to the experiment data is 0.105 MeV. The influence of different input is investigated. It is found that either the shell effect or the pairing effect results in an obvious improvement of the predictive power of ANN model, and the shell effect plays a more important role. The optimal result can be obtained as both the shell and pairing effects are considered simultaneously. Application of ANN model in prediction of the $α$ -decay energy shows the neutron magic number at $N = 184$ , and a possible sub-shell gap around $N = 174$ or 176 in the superheavy nuclei region.
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2203.09412 [pdf]
Symmetry(2022)·3 citations
04
[Submitted on 16 Mar 2022] (cross-list from quant-ph)
Probing confinement in a $Z_{2}$ lattice gauge theory on a quantum computer
Julius Mildenberger🇮🇹 · Wojciech Mruczkiewicz🇺🇸 · Jad C. Halimeh🇮🇹 · Zhang Jiang🇺🇸 · Philipp Hauke🇮🇹
Gauge theories describe the fundamental forces in the standard model of particle physics and play an important role in condensed matter physics. The constituents of gauge theories, for example charged matter and electric gauge field, are governed by local gauge constraints, which lead to key phenomena such as confinement of particles that are not fully understood. In this context, quantum simulators may address questions that are challenging for classical methods. While engineering gauge constraints is highly demanding, recent advances in quantum computing are beginning to enable digital quantum simulations of gauge theories. Here, we simulate confinement dynamics in a $Z_{2}$ lattice gauge theory on a superconducting quantum processor. Tuning a term that couples only to the electric field produces confinement of charges, a manifestation of the tight bond that the gauge constraint generates between both. Moreover, we show how a modification of the gauge constraint from $Z_{2}$ towards $U (1)$ symmetry freezes the system dynamics. Our work illustrates the restriction that the underlying gauge constraint imposes on the dynamics of a lattice gauge theory, it showcases how gauge constraints can be modified and protected, and it promotes the study of other models governed by multi-body interactions.
Comments:
$9 + 12$ pages, $3 + 8$ figures
Subjects:
Quantum Physics (quant-ph); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2203.08905 [pdf]
Nat.Phys.(2025)·190 citations
05
[Submitted on 17 Mar 2022] (cross-list from hep-ph)
Theoretical tools for neutrino scattering: interplay between lattice QCD, EFTs, nuclear physics, phenomenology, and neutrino event generators
L. Alvarez Ruso🇪🇸 · A. M. Ankowski🇺🇸 · S. Bacca🇩🇪 · A. B. Balantekin🇺🇸 · J. Carlson🇺🇸 · S. Gardiner🇺🇸 · R. Gonzalez-Jimenez🇪🇸 · R. Gupta🇺🇸 · T. J. Hobbs🇺🇸 · M. Hoferichter🇨🇭 · J. Isaacson🇺🇸 · N. Jachowicz🇧🇪 and 49 other authors
Maximizing the discovery potential of increasingly precise neutrino experiments will require an improved theoretical understanding of neutrino-nucleus cross sections over a wide range of energies. Low-energy interactions are needed to reconstruct the energies of astrophysical neutrinos from supernovae bursts and search for new physics using increasingly precise measurement of coherent elastic neutrino scattering. Higher-energy interactions involve a variety of reaction mechanisms including quasi-elastic scattering, resonance production, and deep inelastic scattering that must all be included to reliably predict cross sections for energies relevant to DUNE and other accelerator neutrino experiments. This white paper discusses the theoretical status, challenges, required resources, and path forward for achieving precise predictions of neutrino-nucleus scattering and emphasizes the need for a coordinated theoretical effort involved lattice QCD, nuclear effective theories, phenomenological models of the transition region, and event generators.
Comments:
81 pages, contribution to Snowmass 2021
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th); Computational Physics (physics.comp-ph)
arXiv:
2203.09030 [pdf]
J.Phys.G(2025)·104 citations
06
[Submitted on 17 Mar 2022] (cross-list from nucl-ex)
Electromagnetic moments of scandium isotopes and $N = 28$ isotones in the distinctive $0 f_{7/2}$ orbit
S. W. Bai🇨🇳 · Á. Koszorús🇧🇪 · B. S. Hu🇨🇳 · X. F. Yang🇨🇳 · J. Billowes🇬🇧 · C. L. Binnersley🇬🇧 · M. L. Bissell🇬🇧 · K. Blaum🇩🇪 · P. Campbell🇬🇧 · B. Cheal🇬🇧 · T. E. Cocolios🇧🇪 · R. P. de Groote🇫🇮 and 22 other authors
The electric quadrupole moment of $^{49}$ Sc was measured by collinear laser spectroscopy at CERN-ISOLDE to be $Q_{s} = - 0.159 (8)$ $e$ b, and a nearly tenfold improvement in precision was reached for the electromagnetic moments of $^{47, 49}$ Sc. The single-particle behavior and nucleon-nucleon correlations are investigated with the electromagnetic moments of $Z = 21$ isotopes and $N = 28$ isotones as valence neutrons and protons fill the distinctive $0 f_{7/2}$ orbit, respectively, located between magic numbers, 20 and 28. The experimental data are interpreted with shell-model calculations using an effective interaction, and ab-initio valence-space in-medium similarity renormalization group calculations based on chiral interactions. These results highlight the sensitivity of nuclear electromagnetic moments to different types of nucleon-nucleon correlations, and establish an important benchmark for further developments of theoretical calculations.
Comments:
Accepted by Physics Letters B (2022)
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2203.09111 [pdf]
PLB(2022)·9 citations
07
[Submitted on 17 Mar 2022] (cross-list from quant-ph)
Analysis of quantum correlations within the ground state of a three level Lipkin model
Javier Faba🇪🇸 · Vicente Martín🇪🇸 · Luis Robledo🇪🇸
The performance of beyond mean field methods in solving the quantum many body problem for fermions is usually characterized by the correlation energy measured with respect to the underlying mean field value. In this paper we address the issue of characterizing the amount of correlations associated to different approximations from a quantum information perspective. With this goal in mind, we analyze the traditional Hartree-Fock (HF) method with spontaneous symmetry breaking, the HF with symmetry restoration and the generator coordinate method (GCM) in a exactly solvable fermion model known as the three-level Lipkin model. To characterize correlations including entanglement and beyond we use the quantum discord between different partition orbitals. We find that for physically motivated partitions, the quantum discord of the exact ground state is reasonably well reproduced by the different approximations. However, other partitions create "fake quantum correlations" in order to capture quantum correlations corresponding to partitions for which the Hartree-Fock solution fails. Those are removed and redistributed through a symmetry restoration process.
Comments:
13 pages, 9 figures
Subjects:
Quantum Physics (quant-ph); Nuclear Theory (nucl-th)
arXiv:
2203.09400 [pdf]
PRA(2022)·21 citations
08
[Submitted on 17 Mar 2022] (cross-list from hep-ph)
Universality aspects of quantum corrections to transverse momentum broadening in QCD media
Paul Caucal🇺🇸 · Yacine Mehtar-Tani🇺🇸
We study non-linear quantum corrections to transverse momentum broadening (TMB) of a fast parton propagating in dense QCD matter in the leading logarithmic approximation. These non-local corrections yield an anomalous super-diffusive behavior characterized by a heavy tailed distribution which is associated with Lévy random walks. Using a formal analogy with the physics of traveling waves, we show that at late times the transverse momentum distribution tends to a universal scaling regime. We derive analytic solutions in terms of an asymptotic expansion around the scaling limit for both fixed and running coupling. We note that our analytic approach yields a good agreement with the exact numerical solutions down to realistic values of medium length. Finally, we discuss the interplay between system size and energy dependence of the diffusion coefficient $q^$ and its connection with the gluon distribution function that is manifest at large transverse momentum transfer.
Comments:
57 pages, 15 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Statistical Mechanics (cond-mat.stat-mech); Nuclear Theory (nucl-th)
arXiv:
2203.09407 [pdf]
JHEP(2022)·22 citations

Affiliations

first authorsco-authorsvia INSPIRE