Nuclear Theory·nucl-th

Thursday·March 14, 2019

9 papers—6 primary·3 cross-listed

01
[Submitted on 12 Mar 2019]
Local chiral EFT potentials in nuclei and neutron matter: results and issues
Diego Lonardoni · Ingo Tews
In recent years, the combination of advanced quantum Monte Carlo (QMC) methods and local interactions derived from chiral effective field theory (EFT) has been shown to provide a versatile and systematic approach to nuclear systems. Calculations at next-to-next-to-leading order in chiral EFT have lead to fascinating results for nuclei and nucleonic matter. On the one hand, ground-state properties of nuclei are well reproduced up to $A \leq 16$ , even though these potentials have been fit to nucleon-nucleon scattering and few-body observables only. On the other hand, a reasonable description of neutron-matter properties emerges. While regulator functions applied to two- and three-nucleon forces are a necessary ingredient in these many-body calculations, the use of local regulators leads to a substantial residual regulator and cutoff dependence that increases current theoretical uncertainties. In this contribution, we review local chiral interactions, their applications, and QMC results for nuclei and neutron matter. In addition, we address regulator issues for such potentials and present a possible path forward.
Comments:
19 pages, 11 figures, Proceedings of the The 9th International Workshop on Chiral Dynamics (CD18), September 17-21, 2018, Durham, NC, USA
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1903.05215 [pdf]
PoS(2019)·0 citations
02
[Submitted on 13 Mar 2019]
Systematic study of unfavored $α$ decay half-lives of closed shell nuclei related to ground and isomeric states
Jun-Gang Deng · Jie-Cheng Zhao · Dong Xiang · Xiao-Hua Li
In present work, the unfavored $α$ decay half-lives and $α$ preformation probabilities of closed shell nuclei related to ground and isomeric states around $Z = 82$ , $N = 82$ and 126 shell closures are investigated by adopting two-potential approach from the perspective of valence nucleon (hole) and isospin asymmetry of the parent nucleus. The results indicate that $α$ preformation probability is linear dependence on $N_{p} N_{n}$ or $N_{p} N_{n} I$ , the same as the case of favored $α$ decay in our previous work [X.-D. Sun \textit{et al.}, Phys. Rev. C 94, 024338 (2016)]. $N_{p}$ , $N_{n}$ , and $I$ represent the number of valence protons (holes), the number of valence neutrons (holes), and the isospin of the parent nucleus, respectively. Fitting the $α$ preformation probabilities data extracted from the differences between experimental data and calculated half-lives without a shell correction, we give two linear formulas of the $α$ preformation probabilities and the values of corresponding parameters. Based on the formulas and corresponding parameters, we calculate the $α$ decay half-lives for those nuclei. The calculated results can well reproduce the experimental data.
Comments:
7 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1903.05366 [pdf]
PRC(2017)·42 citations
03
[Submitted on 13 Mar 2019]
Non-relativistic conformal symmetry in nuclear structure and relations with the unitarity limit
P. E. Georgoudis🇫🇷
The Interacting Boson Model of nuclear structure is introduced to the unitarity limit. Non relativistic conformal symmetry creates a scale invariant state from which the stationary states of atomic nuclei are obtained. A brief discussion of the nature of the conformal field theory is included along with the BCS-BEC crossover and hydrodynamic properties.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1903.05426 [pdf]
0 citations
04
[Submitted on 13 Mar 2019]
Heavy ion charge exchange reactions and the link with beta decay processes
M.Colonna🇮🇹 · J.I.Bellone🇮🇹 · S.Burrello🇮🇹 · J-A Lay🇪🇸 · H.Lenske🇩🇪
Within the DWBA framework, we develop a theoretical description of single and double heavy ion charge exchange (CE) reactions. We show that absorption effects are particularly important for heavy ion reactions, leading to a noticeable reduction of the CE cross sections. At low momentum transfer, the single CE cross section can be factorised, thus allowing to evaluate corresponding distortion factors and access beta decay strengths. Applications are shown for a system of experimental interest. Preliminary results are discussed also for double CE reactions, modeled as a two-step mechanisms, i.e. a sequence of two charge-changing processes.
Comments:
Proceedings of the 15th International Conference on Nuclear Reaction Mechanisms, Varenna (Italy), June 11-15, 2018 http://dx.doi.org/10.23727/CERN-Proceedings-2019-001
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1903.05441 [pdf]
CERN Proc.(2019)·0 citations
05
[Submitted on 13 Mar 2019]
Opportunities for Nuclear Physics & Quantum Information Science
Ian C. Cloët🇺🇸 · Matthew R. Dietrich🇺🇸 · John Arrington🇺🇸 · Alexei Bazavov🇺🇸 · Michael Bishof🇺🇸 · Adam Freese🇺🇸 · Alexey V. Gorshkov🇺🇸 · Anna Grassellino🇺🇸 · Kawtar Hafidi🇺🇸 · Zubin Jacob🇺🇸 · Michael McGuigan🇺🇸 · Yannick Meurice🇺🇸 and 14 other authors
This whitepaper is an outcome of the workshop Intersections between Nuclear Physics and Quantum Information held at Argonne National Laboratory on 28-30 March 2018 [www.phy.anl.gov/npqi2018/]. The workshop brought together 116 national and international experts in nuclear physics and quantum information science to explore opportunities for the two fields to collaborate on topics of interest to the U.S. Department of Energy (DOE) Office of Science, Office of Nuclear Physics, and more broadly to U.S. society and industry. The workshop consisted of 22 invited and 10 contributed talks, as well as three panel discussion sessions. Topics discussed included quantum computation, quantum simulation, quantum sensing, nuclear physics detectors, nuclear many-body problem, entanglement at collider energies, and lattice gauge theories.
Comments:
22 pages, Outcome of the workshop: Intersections between Nuclear Physics and Quantum Information
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Atomic Physics (physics.atom-ph); Quantum Physics (quant-ph)
arXiv:
1903.05453 [pdf]
48 citations
06
[Submitted on 13 Mar 2019]
Estimates of hyperon polarization in heavy-ion collisions at collision energies $s_{N N} =$ 4--40 GeV
Yu. B. Ivanov🇷🇺 · V. D. Toneev🇷🇺 · A. A. Soldatov🇷🇺
Global polarization of $Λ$ and $Λ ˉ$ hyperons in Au+Au collisions at collision energies $s_{N N} =$ 4-40 GeV in the midrapidity region and total polarization, i.e. averaged over all rapidities, are studied within the scope of the thermodynamical approach. The relevant vorticity is simulated within the model of the three-fluid dynamics (3FD). It is found that the performed rough estimate of the global midrapidity polarization quite satisfactorily reproduces the experimental STAR data on the polarization, especially its collision-energy dependence. The total polarization increases with the collision energy rise, which is in contrast to the decrease of the midrapidity polarization. This suggests that at high collision energies the polarization reaches high values in fragmentation regions.
Comments:
8 pages, 4 figures, minor editing of the text, Fig. 4 changed, version to be published in Phys.Rev.C
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1903.05455 [pdf]
PRC(2019)·72 citations
07
[Submitted on 13 Mar 2019] (cross-list from hep-th)
Extensivity, entropy current, area law and Unruh effect
F. Becattini🇮🇹 · D. Rindori (Florence U.)🇮🇹
We present a general method to determine the entropy current of relativistic matter at local thermodynamic equilibrium in quantum statistical mechanics. Provided that the local equilibrium operator is bounded from below and its lowest lying eigenvector is non-degenerate, it is proved that, in general, the logarithm of the partition function is extensive, meaning that it can be expressed as the integral over a 3D space-like hypersurface of a vector current, and that an entropy current exists. We work out a specific calculation for a non-trivial case of global thermodynamic equilibrium, namely a system with constant comoving acceleration, whose limiting temperature is the Unruh temperature. We show that the integral of the entropy current in the right Rindler wedge is the entanglement entropy.
Comments:
12 pages, 1 figure. Published version in Phys Rev D
Subjects:
High Energy Physics — Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
1903.05422 [pdf]
PRD(2019)·31 citations
08
[Submitted on 13 Mar 2019] (cross-list from cond-mat.quant-gas)
More on the universal equation for Efimov states
M. Gattobigio🇫🇷 · M. Göbel🇩🇪 · H.-W. Hammer🇩🇪 · A. Kievsky🇮🇹
Efimov states are a sequence of shallow three-body bound states that arise when the two-body scattering length is much larger than the range of the interaction. The binding energies of these states are described as a function of the scattering length and one three-body parameter by a transcendental equation involving a universal function of one angular variable. We provide an accurate and convenient parametrization of this function. Moreover, we discuss the effective treatment of range corrections in the universal equation and compare with a strictly perturbative scheme.
Comments:
13 pages, 5 figures
Subjects:
Quantum Gases (cond-mat.quant-gas); Nuclear Theory (nucl-th)
arXiv:
1903.05493 [pdf]
Few Body Syst.(2019)·14 citations
09
[Submitted on 13 Mar 2019] (cross-list from nucl-ex)
High Precision Measurement of Compton Scattering in the 5 GeV region
P. Ambrozewicz🇺🇸 · L. Ye🇺🇸 · Y. Prok🇺🇸 · I. Larin🇷🇺 · A. Ahmidouch🇺🇸 · K. Baker🇺🇸 · V. Baturin🇺🇸 · L. Benton🇺🇸 · A. Bernstein🇺🇸 · V. Burkert🇺🇸 · E. Clinton🇺🇸 · P.L. Cole🇺🇸 and 85 other authors
The cross section of atomic electron Compton scattering $γ + e \to γ^{'} + e^{'}$ was measured in the 4.40--5.475 GeV photon beam energy region by the {\em PrimEx} collaboration at Jefferson Lab with an accuracy of 2\% and less. The results are consistent with theoretical predictions that include next-to-leading order radiative corrections. The measurements provide the first high precision test of this elementary QED process at beam energies greater than 0.1 GeV.
Comments:
6 pages, 4 figures
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1903.05529 [pdf]
PLB(2019)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE