Nuclear Theory·nucl-th

Thursday·November 25, 2021

8 papers—3 primary·5 cross-listed

01
[Submitted on 24 Nov 2021]
Evolution of the phenomenologically determined collective potential along the chain of Zr isotopes
E.V. Mardyban · E.A. Kolganova · T.M. Shneidman · R.V. Jolos
The properties of the collective low-lying states of Zr isotopes which include excitation energies and $E 2$ reduced transition probabilities indicate that some of these states are mainly spherical and the other are mainly deformed ones. We investigate the properties of the low-lying collective states of $^{92 - 102}$ Zr and their evolution with increase of the number of neutrons based on the five-dimensional Geometrical Quadrupole Collective Model. The quadrupole-collective Bohr Hamiltonian with a potential having spherical and deformed minima, is applied. The relative depth of two minima, height and width of the barrier, rigidity of the potential near both minima are determined so as to achieve the best possible description of the observed properties of the low-lying collective quadrupole states of $^{92 - 102}$ Zr. Satisfactory agreement with the experimental data on the excitation energies and the $E 2$ reduced transition probabilities is obtained. The evolution of the collective potential with increase of $A$ is described and the distributions of the wave functions of the collective states in $β - γ$ plane are found. The resulting potential evolves with $A$ increase from having only one spherical minimum in $^{92}$ Zr, through the potentials having both spherical and deformed minima, to the potential with one deformed minimum in $^{102}$ Zr.
Comments:
11 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2111.12402 [pdf]
PRC(2022)·5 citations
02
[Submitted on 24 Nov 2021]
Influence of triaxiality on the description of low-energy excitation spectrum of $^{96}$ Zr
E.V.Mardyban · T.M.Shneidman · E.A.Kolganova · R.V.Jolos
The observed properties of the low-lying collective states of $^{96}$ Zr are investigated within the geometrical collective model. The quadrupole-collective Bohr Hamiltonian with the potential having spherical and axially-symmetric deformed minima is applied. The role of triaxiality is investigated by rotating the potential in $γ$ -degree of freedom so that the deformed minimum occurs at various axially asymmetric shapes. The change of excitation energies and reduced matrix elements of quadrupole transitions with increase of triaxiliaty is analyzed.
Comments:
5 pages, 3 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2111.12410 [pdf]
Phys.Part.Nucl.Lett.(2022)·0 citations
03
[Submitted on 24 Nov 2021]
Universal trend of charge radii of even-even Ca-Zn nuclei
Markus Kortelainen · Zhonghao Sun · Gaute Hagen · Witold Nazarewicz · Thomas Papenbrock · Paul-Gerhard Reinhard
Radii of nuclear charge distributions carry information about the strong and electromagnetic forces acting inside the atomic nucleus. While the global behavior of nuclear charge radii is governed by the bulk properties of nuclear matter, their local trends are affected by quantum motion of proton and neutron nuclear constituents. The measured differential charge radii $δ ⟨ r_{c}^{2} ⟩$ between neutron numbers $N = 28$ and $N = 40$ exhibit a universal pattern as a function of $n = N - 28$ that is independent of the atomic number. Here we analyze this remarkable behavior in even-even nuclei from calcium to zinc using two state-of-the-art theories based on quantified nuclear interactions: the ab-initio coupled cluster theory and nuclear density functional theory. Both theories reproduce the smooth rise of differential charge radii and their weak dependence on the atomic number. By considering a large set of isotopic chains, we show that this trend can be captured by just two parameters: the slope and curvature of $δ ⟨ r_{c}^{2} ⟩ (n)$ . We demonstrate that these parameters show appreciable model dependence, and the statistical analysis indicates that they are not correlated with any single model property, i.e., they are impacted by both bulk nuclear properties as well as shell structure.
Comments:
7 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2111.12464 [pdf]
PRC(2022)·38 citations
04
[Submitted on 23 Nov 2021] (cross-list from hep-ph)
Holographic QCD in the NICER era
Niko Jokela🇺🇸 · Matti Järvinen🇰🇷 · Jere Remes🇪🇸
We analyze families of hybrid equations of state of cold QCD matter, which combine input from gauge/gravity duality and from various ab initio methods for nuclear matter at low density, and predict that all neutron stars are fully hadronic without quark matter cores. We focus on constraints from recent measurements by the NICER telescope on the radius and mass of the millisecond pulsar PSR J0740+6620. These results are found to be consistent with our approach: they set only mild constraints on the hybrid equations of state, and favor the most natural models which are relatively stiff at low density. Adding an upper bound on the maximal mass of neutron stars, as suggested by the analysis of the GW170817 neutron star merger event, tightens the constraints considerably. We discuss updated predictions on observables such as the transition density and latent heat of the nuclear to quark matter transition as well as the masses, radii, and tidal deformabilities of neutron stars.
Comments:
22 pages, 8 figures; v2: refs. added
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2111.12101 [pdf]
PRD(2022)·27 citations
05
[Submitted on 23 Nov 2021] (cross-list from hep-th)
$N = 4$ supersymmetric Yang-Mills thermodynamics from effective field theory
Jens O. Andersen🇳🇴 · Qianqian Du🇨🇳 · Michael Strickland🇺🇸 · Ubaid Tantary🇺🇸
The free energy density of $N = 4$ supersymmetric Yang-Mills theory in four space-time dimensions is derived through second order in the 't Hooft coupling $λ$ at finite temperature using effective-field theory methods. The contributions to the free energy density at this order come from the hard scale $T$ and the soft scale $λ T$ . The effects of the scale $T$ are encoded in the coefficients of an effective three-dimensional field theory that is obtained by dimensional reduction at finite temperature. The effects of the electric scale $λ T$ are taken into account by perturbative calculations in the effective theory.
Comments:
12 pages, 9 figures; v2 - minor typos fixes; published version
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2111.12160 [pdf]
PRD(2022)·13 citations
06
[Submitted on 24 Nov 2021] (cross-list from hep-ph)
Neutrinos and their interactions
M. Sajjad Athar🇮🇳 · S. K. Singh🇮🇳
We present a short overview of the importance of the study of "Neutrino Interactions in the Intermediate and High Energy Region", with an introduction to the neutrinos and a very brief description about the collection of invited articles.
Comments:
7 pages and 2 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2111.12328 [pdf]
Eur.Phys.J.ST(2021)·5 citations
07
[Submitted on 24 Nov 2021] (cross-list from cond-mat.quant-gas)
Detecting Entrainment in Fermi-Bose Mixtures
Khalid Hossain · Subhadeep Gupta · Michael McNeil Forbes
We propose an experimental protocol to directly detect the Andreev-Bashkin effect (entrainment) in the bulk mixture of a bosonic and fermionic superfluid using a ring geometry. Our protocol involves the interferometric detection of the entrainment-induced phase gradient across a superfluid due to the flow of another in which it is immersed. The choice of ring geometry eliminates variations in the stronger mean-field interaction which can thwart the detection of entrainment in other geometries. A significant enhancement of the entrainment phase shift signal is possible, if the dimer-boson scattering length turns out to be large, which can be measured by tuning the interaction to the limit of miscibility of the two superfluids. With suggested improvements and careful design implementation, one may achieve $\approx 67$ % shift in the interferometer fringes.
Comments:
13 pages, 5 figures
Subjects:
Quantum Gases (cond-mat.quant-gas); Nuclear Theory (nucl-th)
arXiv:
2111.12335 [pdf]
PRA(2022)·2 citations
08
[Submitted on 24 Nov 2021] (cross-list from astro-ph.SR)
A moderately-sized nuclear network to assist multi-D hydrodynamic simulations of supernova explosions
Axel Sanz · Rubén Cabezón · Domingo García-Senz
A key ingredient in any numerical study of supernova explosions is the nuclear network routine that is coupled with the hydrodynamic simulation code. When these studies are performed in more than one dimension, the size of the network is severely limited by computational issues. In this work, we propose a nuclear network, net87, which is close to one hundred nuclei and could be appropriate to simulate supernova explosions in multidimensional studies. One relevant feature is that electron and positron captures on free protons and neutrons have been incorporated to the network. Such addition allows for a better track of both, the neutronized species and the gas pressure. A second important feature is that the reactions are implicitly coupled with the temperature, which enhances the stability in the nuclear statistical equilibrium (NSE) regime. Here we analyze the performance of net87 in light of both: the computational overhead of the algorithm and the outcome in terms of the released nuclear energy and produced yields in typical Type Ia Supernova conditions.
Comments:
3 pages, 2 Figures and 1 Table. in Proceedings of The 16th International Symposium on Nuclei in the Cosmos (NIC-XVI)
Subjects:
Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2111.12353 [pdf]
EPJ Web Conf.(2022)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE