Nuclear Theory·nucl-th

Thursday·December 21, 2017

8 papers—4 primary·4 cross-listed

01
[Submitted on 20 Dec 2017]
Influence of the nuclear matter equation of state on the r-mode instability using the finite-range simple effective interaction
S. P. Pattnaik🇮🇳 · T. R. Routray🇮🇳 · X. Viñas🇪🇸 · D. N. Basu🇮🇳 · M. Centelles🇪🇸 · K. Madhuri🇮🇳 · B. Behera🇮🇳
The characteristic physical properties of rotating neutron stars under the r-mode oscillation are evaluated using the finite-range simple effective interaction. Emphasis is given on examining the influence of the stiffness of both the symmetric and asymmetric parts of the nuclear equation of state on these properties. The amplitude of the r-mode at saturation is calculated using the data of particular neutron stars from the considerations of "spin equilibrium" and "thermal equilibrium". The upper limit of the r-mode saturation amplitude is found to lie in the range 10^{-8}-10^{-6}, in agreement with the predictions of earlier work.
Comments:
28 pages, 7 figures, 5 tables
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
1712.07273 [pdf]
J.Phys.G(2018)·15 citations
02
[Submitted on 20 Dec 2017]
Short-range correlation in high-momentum antisymmetrized molecular dynamics
Takayuki Myo
We propose a new variational method for treating short-range repulsion of bare nuclear force for nuclei in antisymmetrized molecular dynamics (AMD). In AMD, the short-range correlation is described in terms of large imaginary centroids of Gaussian wave packets of nucleon pairs in opposite signs, causing high-momentum components in nucleon pair. We superpose these AMD basis states and name this method "high-momentum AMD" (HM-AMD), which is capable of describing strong tensor correlation (Prog. Theor. Exp. Phys. (2017) 111D01). In this paper, we extend HM-AMD by including up to two kinds of nucleon pairs in each AMD basis state utilizing the cluster expansion, which produces many-body correlations involving high-momentum components. We investigate how much HM-AMD describes the short-range correlation by showing the results for $^{3}$ H using the Argonne V4 $^{'}$ central potential. It is found that HM-AMD reproduces the results of few-body calculations and also the tensor-optimized AMD. This means that HM-AMD is a powerful approach to describe the short-range correlation in nuclei. In HM-AMD, momentum directions of nucleon pairs isotropically contribute to the short-range correlation, which is different from the tensor correlation.
Comments:
11 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1712.07457 [pdf]
PTEP(2018)·17 citations
03
[Submitted on 20 Dec 2017]
On the widths and binding energies of $K^{-}$ nuclear states and the role of $K^{-}$ multi-nucleon interactions
J. Hrtankova🇨🇿 · J. Mares🇨🇿
We report on our recent self-consistent calculations of $K^{-}$ nuclear quasi-bound states using $K^{-}$ optical potentials derived from chirally motivated meson-baryon coupled channels models [1,2]. The $K^{-}$ single-nucleon potentials were supplemented by a phenomenological $K^{-}$ multi-nucleon interaction term introduced to achieve good fits to $K^{-}$ atom data. We demonstrate a substantial impact of the $K^{-}$ multi-nucleon absorption on the widths of $K^{-}$ nuclear states. If such states ever exist in nuclear many-body systems, their widths are excessively large to allow observation.
Comments:
9 pages, 5 figures, proceedings of the EXA2017 conference, Vienna, Austria, September 11 - 15, 2017
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1712.07477 [pdf]
EPJ Web Conf.(2018)·0 citations
04
[Submitted on 20 Dec 2017]
Medium effects on freeze-out of light clusters at NICA energies
G. Roepke🇩🇪 · D. Blaschke🇷🇺 · Yu. B. Ivanov🇷🇺 · Iu. Karpenko🇫🇷 · O. V. Rogachevsky🇷🇺 · H. H. Wolter🇩🇪
We estimate the chemical freeze-out of light nuclear clusters for NICA energies of above 2 A GeV. On the one hand we use results from the low energy domain of about 35 A MeV, where medium effects have been shown to be important to explain experimental results. On the high energy side of LHC energies the statistical model without medium effects has provided results for the chemical freeze-out. The two approaches extrapolated to NICA energies show a discrepancy that can be attributed to medium effects and that for the deuteron/proton ratio amounts to a factor of about three. These findings underline the importance of a detailed investigation of light cluster production at NICA energies.
Comments:
10 pages, 4 figures, accepted for publication in Phys. Part. Nucl. Lett; typo in Eq. (6) corrected in v2
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1712.07645 [pdf]
Phys.Part.Nucl.Lett.(2018)·11 citations
05
[Submitted on 4 Dec 2017] (cross-list from cond-mat.str-el)
Consistent hydrodynamic theory of chiral electrons in Weyl semimetals
E. V. Gorbar🇺🇦 · V. A. Miransky🇨🇦 · I. A. Shovkovy🇺🇸 · P. O. Sukhachov🇨🇦
The complete set of Maxwell's and hydrodynamic equations for the chiral electrons in Weyl semimetals is presented. The formulation of the Euler equation takes into account the explicit breaking of the Galilean invariance by the ion lattice. It is shown that the Chern-Simons (or Bardeen-Zumino) contributions should be added to the electric current and charge densities in Maxwell's equations that provide the information on the separation of Weyl nodes in energy and momentum. On the other hand, these topological contributions do not directly affect the Euler equation and the energy conservation relation for the electron fluid. By making use of the proposed consistent hydrodynamic framework, we show that the Chern-Simons contributions strongly modify the dispersion relations of collective modes in Weyl semimetals. This is reflected, in particular, in the existence of distinctive anomalous Hall waves, which are sustained by the local anomalous Hall currents.
Comments:
6+8 pages, 1 figure; published version; a few minor typos in the definitions of $d_{z}$ and $b_{0}$ are corrected
Subjects:
Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1712.01289 [pdf]
PRB(2018)·30 citations
06
[Submitted on 19 Dec 2017] (cross-list from hep-ex)
Muon-neutrino-induced charged current cross section without pions: Theoretical analysis
U. Mosel🇩🇪 · K. Gallmeister🇩🇪
We calculate the charged current cross sections obtained at the T2K near detector for $ν_{μ}$ -induced events without pions in the final state. The method used is quantum-kinetic transport theory. Results are shown first, as a benchmark, for electron inclusive cross sections on $^{12}$ C and $^{16}$ O to be followed with a detailed comparison with the data measured by the T2K collaboration on C $_{8}$ H $_{8}$ and H $_{2}$ O targets. The contribution of 2p2h processes is found to be relevant mostly for backwards angles; their theoretical uncertainties are within the experimental uncertainties. Particular emphasis is then put on a discussion of events in which pions are first created, but then reabsorbed. Their contribution is found to be essential at forward angles.
Comments:
Version essentially identical with published version in Phys. Rev. C
Subjects:
High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1712.07134 [pdf]
PRC(2018)·20 citations
07
[Submitted on 19 Dec 2017] (cross-list from quant-ph)
Fluctuations and correlations in scattering on a resonance coupled to a chaotic background
D. V. Savin
We discuss and briefly overview recent progress with studying fluctuations in scattering on a resonance state coupled to the background of many chaotic states. Such a problem arises naturally, e.g., when dealing with wave propagation in the presence of a complex environment. Using a statistical model based on random matrix theory, we obtain a number of nonperturbative results for various statistics of scattering characteristics. This includes the joint and marginal distributions of the reflection and transmission intensities and phases, which are derived exactly at arbitrary coupling to the background with finite absorption. The intensities and phases are found to exhibit highly non-trivial statistical correlations, which remain essential even in the limit of strong absorption. In the latter case, we also consider the relevant approximations and their accuracy. As an application, we briefly discuss the statistics of the phase rigidity (or mode complexness) in such a scattering situation.
Comments:
7 pages, 4 figures (in the Proceedings of 8th Workshop on Quantum Chaos and Localisation Phenomena, Warsaw, Poland: May 19-21, 2017)
Subjects:
Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Mathematical Physics (math-ph); math.MP (math.MP); Nuclear Theory (nucl-th)
arXiv:
1712.07178 [pdf]
Acta Phys.Polon.A(2017)·2 citations
08
[Submitted on 19 Dec 2017] (cross-list from hep-lat)
Complex Langevin Simulation of a Random Matrix Model at Nonzero Chemical Potential
J. Bloch🇩🇪 · J. Glesaaen🇬🇧 · J. J. M. Verbaarschot🇺🇸 · S. Zafeiropoulos🇩🇪
In this paper we test the complex Langevin algorithm for numerical simulations of a random matrix model of QCD with a first order phase transition to a phase of finite baryon density. We observe that a naive implementation of the algorithm leads to phase quenched results, which were also derived analytically in this article. We test several fixes for the convergence issues of the algorithm, in particular the method of gauge cooling, the shifted representation, the deformation technique and reweighted complex Langevin, but only the latter method reproduces the correct analytical results in the region where the quark mass is inside the domain of the eigenvalues. In order to shed more light on the issues of the methods we also apply them to a similar random matrix model with a milder sign problem and no phase transition, and in that case gauge cooling cooling solves the convergence problems as was shown before in the literature.
Comments:
33 pages, 22 figures
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1712.07514 [pdf]
JHEP(2018)·46 citations

Affiliations

first authorsco-authorsvia INSPIRE