Nuclear Theory·nucl-th

Thursday·November 29, 2018

10 papers—7 primary·3 cross-listed

01
[Submitted on 28 Nov 2018]
Lifting the Veil on Quark Matter in Compact Stars with Core g-mode Oscillations
Wei Wei · Megan Barry · Thomas Klähn · Prashanth Jaikumar
Compact stars containing quark matter may masquerade as neutron stars in the range of measured mass and radius, making it difficult to draw firm conclusions on the phase of matter inside the star. The sensitivity of core $g$ -mode oscillations to the presence of a mixed phase may alleviate this difficulty. In hybrid stars that admit quark matter in a mixed phase, the $g$ -mode frequency rises sharply due to a marked decrease in the equilibrium sound speed. Resonant excitation of $g$ -modes can leave an imprint on the waveform of coalescing binary compact stars. We present some analytic and numeric results to assess the sensitivity displayed by $g$ -mode oscillations to quark matter in a homogeneous or mixed phase and find that the $g$ -mode can probe the fraction of quark matter inside the star.
Comments:
11 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1811.11377 [pdf]
ApJ(2020)·39 citations
02
[Submitted on 28 Nov 2018]
Thermal Production of Charmonia at the LHC Energies
Baoyi Chen
This work studies the thermal production of $J / ψ$ and $ψ (2 S)$ with Boltzmann transport model in the Quark Gluon Plasma (QGP) produced in $s_{N N} = 5.02$ TeV Pb-Pb collisions. $J / ψ$ nuclear modification factors are studied in details with the mechanisms of primordial production and the recombination of charm and anti-charm quarks in the thermal medium. $ψ (2 S)$ binding energy is much smaller in the hot medium compared with the ground state, so $ψ (2 S)$ with middle and low $p_{T}$ can be mainly thermally regenerated in the later stage of QGP expansions which enables $ψ (2 S)$ inherit larger collective flows from the bulk medium. We quantitatively study both nuclear modification factors of $J / ψ$ and $ψ (2 S)$ in different centralities and transverse momentum bins in $s_{N N} = 5.02$ TeV Pb-Pb collisions.
Comments:
9 pages, 12 figures. Published version in Chinese Physics C
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1811.11393 [pdf]
CPC(2019)·38 citations
03
[Submitted on 28 Nov 2018]
Gaussian-distribution analysis of transverse momentum spectra of K_0^S and K^(*0) in 200 GeV collisions
Zhi-hao Pan🇨🇳 · Si-you Guo🇨🇳 · B. C. Li🇨🇳
In this paper, we use the Gaussian distribution to analyze transverse momentum spectra of K_0^S and K^(*0) at midrapidity in d +Au, Cu+Cu and p+p Collisions at 200 GeV. The two-component Gaussian distribution can approximately agree with the experimental data and the three-component distribution can perfectly agree with the data in the given range. Moreover, there is a significantly positive correlation between the temperature and the collision centrality.
Comments:
9 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1811.11434 [pdf]
0 citations
04
[Submitted on 28 Nov 2018]
The propagation of statistical errors in covariant density functional theory: ground state observables and single-particle properties
S.\ E.\ Agbemava · A.\ V.\ Afanasjev andA.\ Taninah
Statistical errors in ground state observables and single-particle properties of spherical even-even nuclei and their propagation to the limits of nuclear landscape have been investigated in covariant density functional theory (CDFT) for the first time. In this study we consider only covariant energy density functionals with non-linear density dependency. Statistical errors for binding energies and neutron skins significantly increase on approaching two-neutron drip line. On the contrary, such a trend does not exist for statistical errors in charge radii and two-neutron separation energies. The absolute and relative energies of the single-particle states in the vicinity of the Fermi level are characterized by low statistical errors ( $σ (e_{i}) \sim 0.1$ MeV). Statistical errors in the predictions of spin-orbit splittings are rather small. Statistical errors in physical observables are substantially smaller than related systematic uncertainties. Thus, at the present level of the development of theory, theoretical uncertainties at nuclear limits are dominated by systematic ones. Statistical errors in the description of physical observables related to the ground state and single-particle degrees of freedom are typically substantially lower in CDFT as compared with Skyrme density functional theory. The correlations between the model parameters are studied in detail. The parametric correlations are especially pronounced for the $g_{2}$ and $g_{3}$ parameters which are responsible for the density dependence of the model. The accounting of this fact potentially allows to reduce the number of free parameters of non-linear meson coupling model from six to five.
Comments:
18 pages, 9 figures, submitted to Physical Review C, referee suggestions are taken into account
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1811.11473 [pdf]
PRC(2019)·23 citations
05
[Submitted on 28 Nov 2018]
Cluster structures, ellipsoidal shapes and nuclear molecules in light A=12-50 nuclei
A. V. Afanasjev
The transition from cluster structures to extremely elongated ellipsoidal shapes and nuclear molecules in light $A = 12 - 50$ $(N \sim Z)$ nuclei has been studied within the framework of covariant density functional theory. Nodal structure of the occupied single-particle states plays a critical role in microscopic understanding of this transition. This is illustrated by the analysis of dominant types of single-particle density distributions and their evolution (from the bottom of nucleonic potential) with deformation and particle number. The microscopic mechanism of the transition from clustered structures to ellipsoidal shapes and nuclear molecules and between them is discussed.
Comments:
EPJ Web of Conferences 194, 06001 (2018), 6 pages
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1811.11480 [pdf]
EPJ Web Conf.(2018)·3 citations
06
[Submitted on 28 Nov 2018]
Recent Theoretical Advances and Open Problems in Nuclear Cluster Physics
P.Schuck🇫🇷
This contribution gives a short review of recent theoretical advances in most topics of nuclear cluster physics concentrating, however, around { $α$ } particle clustering. Along the route, the point of view will be critical mentioning not only progress but also failures and open problems.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1811.11580 [pdf]
AIP Conf.Proc.(2018)·8 citations
07
[Submitted on 28 Nov 2018]
Consequences of conformal anomaly on fluid dynamics
Alina Czajka🇵🇱
We review a recent progress on fluid dynamics applied to strongly interacting nuclear matter. The efforts are made to highlight consequences of scale invariance breaking on the hydrodynamic description of a nuclear medium. Both phenomenological and analytical findings are summarized.
Comments:
10 pages, proceedings of "XIII Quark Confinement and the Hadron Spectrum - Confinement2018", 31 July - 6 August 2018, Maynooth University, Ireland
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1811.11641 [pdf]
PoS(2018)·0 citations
08
[Submitted on 26 Nov 2018] (cross-list from nucl-ex)
Cross Sections for A(e,e')X Reactions
U. Mosel🇩🇪 · K. Gallmeister🇩🇪
Recent JLAB measurements of inclusive (e,A) cross sections as a function of outgoing lepton momentum may provide information on the nucleon spectral function in targets that will be relevant for the planned DUNE neutrino long-baseline experiment. They also provide an important testing ground for neutrino generators. We have therefore used the transport theoretical framework and code GiBUU to calculate the cross sections for the targets C, Ar and Ti. We compare the calculations with the experimental data. The overall agreement is good. Relatively small discrepancies appear mainly on the low-electronenergy side of the QE-peak where QE and 2p2h excitation processes overlap.
Comments:
2 new refs added, note added in proof, otherwise unchanged
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1811.10637 [pdf]
PRC(2019)·14 citations
09
[Submitted on 27 Nov 2018] (cross-list from hep-ph)
Nucleon matrix elements of the antisymmetric quark tensor
Martin Hoferichter🇺🇸 · Bastian Kubis🇩🇪 · Jacobo Ruiz de Elvira🇨🇭 · Peter Stoffer🇺🇸
If physics beyond the Standard Model enters well above the electroweak scale, its low-energy effects are described by Standard Model Effective Field Theory. Already at dimension six many operators involve the antisymmetric quark tensor $q ˉ σ^{μν} q$ , whose matrix elements are difficult to constrain from experiment, Ward identities, or low-energy theorems, in contrast to the corresponding vector and axial-vector or even scalar and pseudoscalar currents. However, with normalizations determined from lattice QCD, analyticity and unitarity often allow one to predict the momentum dependence in a large kinematic range. Starting from recent results in the meson sector, we extend this method to the nucleon case and, in combination with pole dominance, provide a comprehensive assessment of the current status of the nucleon form factors of the quark tensor.
Comments:
7 pages, 3 figures; strangeness input updated
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
1811.11181 [pdf]
PRL(2019)·46 citations
10
[Submitted on 28 Nov 2018] (cross-list from hep-th)
Thermal effective potential for the Polyakov loop to higher loop order
Hiromichi Nishimura🇺🇸 · Chris Korthals-Altes🇳🇱 · Robert D. Pisarski🇺🇸 · Vladimir Skokov🇺🇸
This is a progress report on the calculation of the effective potential for the Polyakov loop in $S U (N)$ pure gauge theory beyond two-loop order. We introduce a new approach using the Poisson resummation formula to compute sum-integrals with the holonomy. We show partial results for the free energy at order $g^{3}$ and $g^{4}$ .
Comments:
9 pages, 1 figure, conference proceeding for XIII Quark Confinement and the Hadron Spectrum - Confinement2018
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1811.11736 [pdf]
PoS(2019)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE