Nuclear Theory·nucl-th

Tuesday·August 23, 2016

8 papers—4 primary·4 cross-listed

01
[Submitted on 21 Aug 2016]
Shell Model States in the Continuum
A. M. Shirokov · A. I. Mazur · I. A. Mazur · J. P. Vary
We suggest a method for calculating scattering phase shifts and energies and widths of resonances which utilizes only eigenenergies obtained in variational calculations with oscillator basis and their dependence on oscillator basis spacing $ℏΩ$ . We make use of simple expressions for the $S$ -matrix at eigenstates of a finite (truncated) Hamiltonian matrix in the oscillator basis obtained in the HORSE ( $J$ -matrix) formalism of quantum scattering theory. The validity of the suggested approach is verified in calculations with model Woods--Saxon potentials and applied to calculations of $n α$ resonances and non-resonant scattering using the no-core shell model.
Comments:
Revision due to journal referee recommendations; 26 pages, 52 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1608.05885 [pdf]
PRC(2016)·54 citations
02
[Submitted on 21 Aug 2016]
Chiral EFT based nuclear forces: Achievements and challenges
R. Machleidt🇺🇸 · F. Sammarruca
During the past two decades, chiral effective field theory has become a popular tool to derive nuclear forces from first principles. Two-nucleon interactions have been worked out up to sixth order of chiral perturbation theory and three-nucleon forces up to fifth order. Applications of some of these forces have been conducted in nuclear few- and many-body systems---with a certain degree of success. But in spite of these achievements, we are still faced with great challenges. Among them is the issue of a proper uncertainty quantification of predictions obtained when applying these forces in {\it ab initio} calculations of nuclear structure and reactions. A related problem is the order by order convergence of the chiral expansion. We start this review with a pedagogical introduction and then present the current status of the field of chiral nuclear forces. This is followed by a discussion of representative examples for the application of chiral two- and three-body forces in the nuclear many-body system including convergence issues.
Comments:
66 pages, 28 figures. Invited contribution to Special Physica Scripta Edition commemorating the 40-th Anniversary of the Nobel Prize for Bohr, Mottelson, and Rainwater
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1608.05978 [pdf]
Phys.Scripta(2016)·112 citations
03
[Submitted on 22 Aug 2016]
The fluctuations of quadrangular flow
Giuliano Giacalone🇫🇷 · Li Yan🇫🇷 · Jacquelyn Noronha-Hostler🇺🇸 · Jean-Yves Ollitrault🇫🇷
The ATLAS Collaboration has measured for the first time the fourth cumulant of quadrangular flow, $v_{4} {4}^{4}$ . Unlike the fourth cumulants of elliptic and triangular flows, it presents a change of sign above 30\% centrality. We show that this change of sign is predicted by event-by-event hydrodynamics. We argue that it results from the combined effects of a nonlinear hydrodynamic response, which couples quadrangular flow to elliptic flow, and elliptic flow fluctuations.
Comments:
4 pages. 2 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1608.06022 [pdf]
J.Phys.Conf.Ser.(2017)·15 citations
04
[Submitted on 22 Aug 2016]
Three-body antikaon-nucleon systems
N.V. Shevchenko🇨🇿
The paper contains a review of the exact or accurate results achieved in the field of the three-body antikaon-nucleon physics. Different states and processes in $K ˉ N N$ and $K ˉ K ˉ N$ systems are considered. In particular, quasi-bound states in $K^{-} pp$ and $K^{-} K^{-} p$ systems were investigated together with antikaonic deuterium atom. Near-threshold scattering of antikaons on deuteron, including the $K^{-} d$ scattering length, and applications of the scattering amplitudes are also discussed. All exact three-body results were calculated using some form of Faddeev equations. Different versions of $K ˉ N$ , $Σ N$ , $K ˉ K ˉ$ , and $N N$ potentials, specially constructed for the calculations, allowed investigation of the dependence of the three-body results on the two-body input. Special attention is paid to the antikaon-nucleon interaction, being the most important for the three-body systems. Approximate calculations, performed additionally to the exact ones, demonstrate accuracy of the commonly used approaches.
Comments:
27 pages, 2 figures, 5 tables; modified version accepted for publication in Few-Body Systems journal
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1608.06126 [pdf]
Few Body Syst.(2017)·25 citations

Affiliations

first authorsco-authorsvia INSPIRE

Shell Model States in the Continuum

Chiral EFT based nuclear forces: Achievements and challenges

The fluctuations of quadrangular flow

Three-body antikaon-nucleon systems

Affiliations