Nuclear Theory·nucl-th

Tuesday·February 25, 2020

10 papers—7 primary·3 cross-listed

01
[Submitted on 21 Feb 2020]
Three-Nucleon Forces: Implementation and Applications to Atomic Nuclei and Dense Matter
Kai Hebeler🇩🇪
Recent advances in nuclear structure theory have significantly enlarged the accessible part of the nuclear landscape via ab initio many-body calculations. These developments open new ways for microscopic studies of light, medium-mass and heavy nuclei as well as nuclear matter and represent an important step toward a systematic and comprehensive understanding of atomic nuclei across the nuclear chart. While remarkable agreement has been found between different many-body methods for a given nuclear Hamiltonian, the comparison with experiment and the understanding of theoretical uncertainties are still important open questions. The observed discrepancies to experiment indicate deficiencies in presently used nuclear interactions and operators. Chiral effective field theory (EFT) allows to systematically derive contributions to nucleon-nucleon (NN), three-nucleon (3N) and higher-body interactions including estimates of theoretical uncertainties. While the treatment of NN interactions in many-body calculations is well established, the calculation of 3N interactions and their incorporation in ab initio frameworks is still a frontier. This work reviews in detail recent and current developments on the derivation and implementation of improved 3N interactions and provides a comprehensive introduction to fundamental methods for their practical calculation and representation. We further give an overview of novel and established methods that facilitate the inclusion and treatment of 3N interactions in ab initio nuclear structure frameworks and present a selection of the latest calculations of atomic nuclei as well as nuclear matter based on state-of-the-art nuclear NN and 3N interactions derived within chiral EFT. Finally, we discuss ongoing efforts, open questions and future directions.
Comments:
148 pages, 77 figures, 9 tables, published version
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Experiment (nucl-ex)
arXiv:
2002.09548 [pdf]
Phys.Rept.(2021)·179 citations
02
[Submitted on 22 Feb 2020]
Accelerating longitudinal expansion of resistive relativistic-magneto-hydrodynamics in heavy ion collisions
M. Haddadi Moghaddam🇮🇹 · W. M. Alberico🇮🇹 · Duan She🇨🇳 · A. F. Kord🇮🇷 · B. Azadegan🇮🇷
We study the evolution of the longitudinal expansion of an ideal fluid with finite electrical conductivity, which is subject to the EM fields. In the framework of resistive relativistic-magneto-hydrodynamic, we find an exact analytical solution for the EM fields and for the acceleration of the fluid.
Comments:
9 pages, 12 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Theory (hep-th)
arXiv:
2002.09752 [pdf]
PRD(2020)·6 citations
03
[Submitted on 22 Feb 2020]
Ultrarelativistic quark-nucleus scattering in a light-front Hamiltonian approach
Meijian Li🇺🇸 · Xingbo Zhao🇨🇳 · Pieter Maris🇺🇸 · Guangyao Chen🇺🇸 · Yang Li🇺🇸 · Kirill Tuchin🇺🇸 · James P. Vary🇺🇸
We investigate the scattering of a quark on a heavy nucleus at high energies using the time-dependent basis light-front quantization (tBLFQ) formalism, which is the first application of the tBLFQ formalism in QCD. We present the real-time evolution of the quark wave function in a strong classical color field of the relativistic nucleus, described as the Color Glass Condensate. The quark and the nucleus color field are simulated in the QCD SU(3) color space. We calculate the total and the differential cross sections, and the quark distribution in coordinate and color spaces using the tBLFQ approach. We recover the eikonal cross sections in the eikonal limit. We find that the differential cross section from the tBLFQ simulation is in agreement with a perturbative calculation at large $p_{⊥}$ , and it deviates from the perturbative calculation at small $p_{⊥}$ due to higher-order contributions. In particular, we relax the eikonal limit by letting the quark carry realistic finite longitudinal momenta. We study the sub-eikonal effect on the quark through the transverse coordinate distribution of the quark with different longitudinal momentum, and we find the sub-eikonal effect to be sizable. Our results can significantly reduce the theoretical uncertainties in small $p_{⊥}$ region which has important implications to the phenomenology of the hadron-nucleus and deep inelastic scattering at high energies.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2002.09757 [pdf]
PRD(2020)·38 citations
04
[Submitted on 24 Feb 2020]
Nuclear multipole responses from chiral effective field theory interaction
B. S. Hu · Q. Wu · Q. Yuan · Y. Z. Ma · X. Q. Yan · F. R. Xu
We probe nuclear multipole resonances in the framework of the random-phase approximation by using the interaction obtained from the chiral effective field theory. The three-nucleon force is included in a form of the in-medium two-nucleon interaction which was derived from the chiral three-nucleon force. The isoscalar monopole, isoscalar dipole, isovector dipole and isoscalar quadrupole resonances of the closed-shell $^{56, 68, 78}$ Ni have been investigated. The calculations reasonably reproduce the experimental multipole resonances of $^{56, 68}$ Ni, and well describe the pygmy dipole resonance and dipole polarizability measured in $^{68}$ Ni. The multipole resonances of $^{78}$ Ni, including pygmy dipole resonance and dipole polarizability, are predicted. The detailed effects of the tensor force and three-body force are analyzed by dissecting the chiral interaction. We find that in general the tensor force effect on electric giant resonances is not as significant as the effect from the three-body force, although the tensor force provides more than half of the binding energy. The effect from three-body force is strong in light nuclei. Particularly, three-body force is crucial for the formation of the pygmy resonance in calculations.
Comments:
Accepted by PHYSICAL REVIEW C
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2002.10048 [pdf]
PRC(2020)·8 citations
05
[Submitted on 24 Feb 2020]
Signatures of the vortical quark-gluon plasma in hadron yields
ExHIC-P Collaboration · Hidetoshi Taya · Aaron Park · Sungtae Cho · Philipp Gubler · Koichi Hattori · Juhee Hong · Xu-Guang Huang · Su Houng Lee · Akihiko Monnai · Akira Ohnishi · Makoto Oka · Di-Lun Yang
We investigate the hadron production from the vortical quark-gluon plasma created in heavy-ion collisions. Based on the quark-coalescence and statistical hadronization models, we show that total hadron yields summed over the spin components are enhanced by the local vorticity with quadratic dependence. The enhancement factor amounts to be a few percent and may be detectable within current experimental sensitivities. We also show that the effect is stronger for hadrons with larger spin, and thus propose a new signature of the local vorticity, which may be detected by the yield ratio of distinct hadron species having different spins such as $ϕ$ and $η^{'}$ . The vorticity dependence of hadron yields seems robust, with consistent predictions in both of the hadron production mechanisms for reasonable values of the vorticity strength estimated for heavy-ion collisions.
Comments:
6 pages, 2 figures; v2: summary and discussions improved, references updated, to be published in PRC
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2002.10082 [pdf]
PRC(2020)·14 citations
06
[Submitted on 24 Feb 2020]
Trees and Forests in Nuclear Physics
Marco Carnini · Alessandro Pastore
We present a simple introduction to the decision tree algorithm using some examples from nuclear physics. We show how to improve the accuracy of the classical liquid drop nuclear mass model by performing Feature Engineering with a decision tree. Finally, we apply the method to the Duflo-Zuker model showing that, despite their simplicity, decision trees are capable of improving the description of nuclear masses using a limited number of free parameters.
Subjects:
Nuclear Theory (nucl-th); Machine Learning (cs.LG); Nuclear Experiment (nucl-ex)
arXiv:
2002.10290 [pdf]
J.Phys.G(2020)·22 citations
07
[Submitted on 24 Feb 2020]
Reanalysis of $^{13}$ N( $p, γ$ ) $^{14}$ O reaction and its role in stellar CNO cycle
S. B. Dubovichenko · R. Ya. Kezerashvili · N. A. Burkova · A. V. Dzhazairov-Kakhramanov · B. Beisenov
Within the framework of the modified potential cluster model with forbidden states, the $^{13}$ N( $p, γ$ ) $^{14}$ O reaction rate and the astrophysical $S$ -factor are considered. It is shown that the first $p^{13}$ % N resonance determines the $S$ -factor and contributions of the $M 1$ and $E 2$ transitions are negligible at energies $E < 1$ MeV, but are significant at high energies. The $S$ -factor strongly depends on the $^{3} S_{1}$ resonance parameters. The influence of the width of \ the $^{3} S_{1}$ resonance on $S$ % -factor is demonstrated. The reaction rate is calculated and an analytical approximation for the reaction rate is proposed. A comparison of our calculation with existing data is addressed. Results of our calculations for the $^{13}$ N( $p, γ)^{14}$ O reaction rate provide the contribution to the steadily improving reaction rate database libraries. Our calculations of the N( $p, γ)^{14}$ O reaction rate along with results for the rates of $^{14}$ N(O and $^{12}$ C $(p, γ)^{13}$ N processes provide the temperature range $0.13 < T_{9} < 0.97$ for the conversion of CNO cycle to the HCNO cycle. Our results demonstrate that at early stages of a nova explosion at temperatures about $0.1$ $T_{9}$ and at late stages of evolution of supermassive stars at temperatures about $1.0$ $T_{9}$ the ignition of the HCNO cycle could occur at much lower densities of a stellar medium.
Comments:
19 pages, 8 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2002.10308 [pdf]
PRC(2020)·4 citations
08
[Submitted on 23 Feb 2020] (cross-list from physics.data-an)
Bryan's Maximum Entropy Method -- diagnosis of a flawed argument and its remedy
Alexander Rothkopf
The Maximum Entropy Method (MEM) is a popular data analysis technique based on Bayesian inference, which has found various applications in the research literature. While the MEM itself is well-grounded in statistics, I argue that its state-of-the-art implementation, suggested originally by Bryan, artificially restricts its solution space. This restriction leads to a systematic error often unaccounted for in contemporary MEM studies. The goal of this paper is to carefully revisit Bryan's train of thought, point out its flaw in applying linear algebra arguments to an inherently nonlinear problem, and suggest possible ways to overcome it.
Comments:
16 pages, 3 figures, peer reviewed and published version
Subjects:
Data Analysis, Statistics and Probability (physics.data-an); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Computational Physics (physics.comp-ph)
arXiv:
2002.09865 [pdf]
Data 2020, 5(3), 85·9 citations
09
[Submitted on 23 Feb 2020] (cross-list from hep-ph)
The Collectivity of Heavy Mesons in Proton-Nucleus Collisions
Cheng Zhang🇨🇳 · Cyrille Marquet🇫🇷 · Guang-You Qin🇨🇳 · Yu Shi🇨🇳 · Lei Wang🇨🇳 · Shu-Yi Wei🇫🇷 · Bo-Wen Xiao🇨🇳
Using a model based on the Color Glass Condensate framework and the dilute-dense factorization, we systematically study the azimuthal angular correlations between a heavy flavor meson and a light reference particle in proton-nucleus collisions. The obtained second harmonic coefficients (also known as the elliptic flows) for $J / ψ$ and $D^{0}$ agree with recent experimental data from the LHC. We also provide predictions for the elliptic flows of $Υ$ and $B$ meson, which can be measured in the near future at the LHC. This work can shed light on the physics origin of the collectivity phenomenon in the collisions of small systems.
Comments:
14 pages, 7 figures. This work is an extension of our earlier publication 10.1103/PhysRevLett.122.172302 (arXiv:1901.10320); v2 with minor updates
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2002.09878 [pdf]
PRD(2020)·37 citations
10
[Submitted on 24 Feb 2020] (cross-list from nucl-ex)
Chiral Magnetic Effects in Nuclear Collisions
Wei Li🇺🇸 · Gang Wang🇺🇸
The interplay of quantum anomalies with strong magnetic field and vorticity in chiral systems could lead to novel transport phenomena, such as the chiral magnetic effect (CME), the chiral magnetic wave (CMW) and the chiral vortical effect (CVE). In high-energy nuclear collisions, these chiral effects may survive the expansion of a quark-gluon plasma fireball and be detected in experiments. The experimental searches for the CME, the CMW and the CVE, have aroused extensive interest over the past couple of decades. The main goal of this article is to review latest experimental progress in search for these novel chiral transport phenomena at Relativistic Heavy Ion Collider at BNL and the Large Hadron Collider at CERN. Future programs to help reduce uncertainties and facilitate the interpretation of the data are also discussed.
Comments:
Invited review for Annual Review of Nuclear and Particle Science, 28 pages, 11 figures. Comments are welcome!
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2002.10397 [pdf]
Ann.Rev.Nucl.Part.Sci.(2020)·71 citations

Affiliations

first authorsco-authorsvia INSPIRE