Nuclear Theory·nucl-th

Tuesday·April 12, 2022

7 papers—3 primary·4 cross-listed

01
[Submitted on 9 Apr 2022]
Isospin dependent properties of the isotopic chain of Scandium and Titanium nuclei within the relativistic mean-field formalism
Praveen K. Yadav · Raj Kumar · M. Bhuyan
The density-dependent nuclear symmetry energy is directly related to the isospin asymmetry for finite and infinite nuclear systems. It is critical to determine the coefficients of symmetry energy and its related observables as it holds great importance in different areas of nuclear physics, such as analyzing the structure of ground state exotic nuclei and neutron star study. The ground state bulk properties such as nuclear binding energy, quadrupole deformation, two-neutron separation energy, the differential variation of two-neutron separation energy, and root-mean-square charge radius for Scandium (Z = 21), and Titanium (Z = 22) nuclei are calculated. The coherent density fluctuation model is used to estimate the isospin-dependent properties of finite nuclei such as symmetry energy and its surface and volume components from its corresponding value in infinite nuclear matter system. Finally, we correlate the neutron-skin thickness with the coefficient of symmetry energy and its related observables corresponding to these isotopic chains of nuclei. The relativistic mean-field formalism with non-linear NL3 and Relativistic-Hartree-Bogoliubov with density-dependent DD-ME2 interaction parameters are employed in the present analysis. A shape transition is observed from spherical to prolate near N $\geq$ 44 and N $\geq$ 40 for Sc- and Ti- isotopic chain, respectively. Notable signatures of shell and/or sub-shell closures have been found for the magic neutron numbers at N = 20 and 28 for both the isotopic chain using the nuclear bulk and isospin quantities. In addition to these, a few signatures of shell/sub-shell closure are observed near the drip-line region, at N = 34 and 50 by following the surface/isospin dependent observables, namely symmetry energy and its component for both the isotopic chain of odd-A Sc- and even-even Ti- nuclei.
Comments:
Submitted to Chinese Physics C: 15 pages, 10 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2204.04485 [pdf]
CPC(2022)·15 citations
02
[Submitted on 11 Apr 2022]
The optimized point-coupling interaction for the relativistic energy density functional of Hartree-Bogoliubov approach quantifying the nuclear bulk properties
Zi Xin Liu · Yi Hua Lam · Ning Lu · Peter Ring
We propose a newly optimized nonlinear point-coupling parameterized interaction, PC-L3R, for the relativistic Hartree-Bogoliubov framework with a further optimized separable pairing force by fitting to observables, i.e., the binding energies of 91 spherical nuclei, charge radii of 63 nuclei, and 12 sets of mean pairing gaps consisting of 54 nuclei in total. The separable pairing force strengths of proton and neutron are optimized together with the point-coupling constants, and are justified in satisfactory reproducing the empirical pairing gaps. The comparison of experimental binding energies compiled in AME2020 for 91 nuclei with the ones generated from the present and other commonly used point-coupling interactions indicates that the implementation of PC-L3R in relativistic Hartree-Bogoliubov yields the lowest root-mean-square deviation. The charge radii satisfactory agree with experiment. Meanwhile, PC-L3R is capable of estimating the saturation properties of the symmetric nuclear matter and of appropriately predicting the isospin and mass dependence of binding energy. The experimental odd-even staggering of single nucleon separation energies is well reproduced. The comparison of the estimated binding energies for 7,373 nuclei based on the PC-L3R and other point-coupling interactions is also presented.
Comments:
Accepted by Physics Letters B on 30 April 2023. To appear at Physics Letters B (Open Access). 16 pages, 11 figures (colorblind-friendly colors), 7 tables. This version presents the PC-L3R interaction. The first version (arXiv:2204.05159v1) presents the PC-L3 interaction
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2204.05159 [pdf]
PLB(2023)·15 citations
03
[Submitted on 11 Apr 2022]
Hyperons, deconfinement and the speed of sound in neutron stars
R. M. Aguirre🇦🇷
The effects of the presence of hyperons and a phase transition to deconfined quark matter on the speed of sound in neutron stars is investigated. For this purpose a composite description consisting of a model of the covariant field theory of hadrons and one for unbound quarks are used. A phase transition with continuous and monotonous variation of the equation of state is assumed. The predictions are contrasted with recent observational data on isolated neutron stars as well as on binary systems. Only one candidate is finally obtained from six different descriptions. According to the present calculations the onset of the hyperons causes the equilibrium speed of sound to exceed the conformal limit. Qualitative agreement with recent work about the influence of the speed of sound on the g-modes of oscillation in neutron stars is obtained.
Comments:
Matches the published version
Subjects:
Nuclear Theory (nucl-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2204.05221 [pdf]
PRD(2022)·10 citations
04
[Submitted on 10 Apr 2022] (cross-list from hep-ph)
Neutron-neutral particle mixing and its observable consequences
Yongliang Hao🇨🇳 · Dongdong Ni🇨🇳
In this work, we explore the mixing between neutron ( $n$ ) and elementary neutral particle ( $η$ ), which violates both the baryon number ( $B$ ) and the lepton number ( $L$ ) by one unit but conserves their difference $(B - L)$ . Such mixing may give rise to non-trivial effects that are different from the Standard Model predictions. We organize our discussions based on two scenarios, roughly depending on whether an interference between oscillation and decay occurs, or whether the new-physics effects associated with the $n$ - $η$ mixing contribute to the absorptive mixing amplitude. If an oscillation process is not accompanied by an interference between oscillation and decay, or the new-physics interactions do not contribute to the absorptive mixing amplitude, such a process can be classified as pure oscillation. Otherwise, it can be classified as impure oscillation. In the scenario of pure oscillation, CP-violation arising from the Majorana phase can manifest itself through the $n$ - $n ˉ$ oscillation process and may lead to observable effects. In the scenario of impure oscillation, we analyze the testable implications on the masses and lifetimes of the mass eigenstates formed as a result of the $n$ - $n ˉ$ oscillation mediated by $η$ . In this scenario, we also suggest a unified interpretation of the neutron lifetime anomaly and the $n$ - $n ˉ$ oscillation measurements based on the $n$ - $η$ mixing. In both scenarios, we present the lower bounds imposed by the experimental searches for $n$ - $n ˉ$ oscillations on the masses of the color multiplet bosons and point out that they could be within the reach of a direct detection at the LHC or future high-energy experiments.
Comments:
18 pages, 6 figures and 2 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2204.04713 [pdf]
PRD(2022)·6 citations
05
[Submitted on 11 Apr 2022] (cross-list from hep-lat)
Spurious poles in a finite volume
Jin-Yi Pang🇨🇳 · Martin Ebert🇩🇪 · Hans-Werner Hammer🇩🇪 · Fabian Müller🇩🇪 · Akaki Rusetsky🇩🇪 · Jia-Jun Wu🇨🇳
Using effective-range expansion for the two-body amplitudes may generate spurious sub-threshold poles outside of the convergence range of the expansion. In the infinite volume, the emergence of such poles leads to the inconsistencies in the three-body equations, e.g., to the breakdown of unitarity. We investigate the effect of the spurious poles on the three-body quantization condition in a finite volume and show that it leads to a peculiar dependence of the energy levels on the box size $L$ . Furthermore, within a simple model, it is demonstrated that the procedure for the removal of these poles, which was recently proposed in Ref.[1] in the infinite volume, can be adapted to the finite-volume calculations. The structure of the exact energy levels is reproduced with an accuracy that systematically improves order by order in the EFT expansion.
Comments:
26 pages, 9 figures
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2204.04807 [pdf]
JHEP(2022)·9 citations
06
[Submitted on 11 Apr 2022] (cross-list from hep-lat)
Impact of Dynamical Fermions on Centre Vortex Structure
Derek Leinweber🇦🇺 · James Biddle🇦🇺 · Waseem Kamleh (University of Adelaide)🇦🇺
This presentation examines the centre vortex structure of Monte-Carlo generated gauge-field configurations using modern visualisation techniques. This time, the manner in which light dynamical fermion degrees of freedom impact the centre-vortex structure is explored. Focusing on the thin vortices identified by plaquettes having a non-trivial centre phase, the vortex structure is illustrated through 3D renderings of oriented plaquettes. The impact of light dynamical fermions is not subtle, changing both the density of vortices and the complexity of the vortex structures observed. The role of vortex branching points in full QCD is highlighted in the survey of results presented.
Comments:
9 pages, 5 figures with 4 3D interactive. Proceedings of the 38th International Symposium on Lattice Field Theory (Lattice 2021), 26th - 30th July 2021, Zoom/Gather@Massachusetts Institute of Technology
Subjects:
High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2204.04825 [pdf]
PoS(2022)·3 citations
07
[Submitted on 11 Apr 2022] (cross-list from hep-ph)
Chiral spin symmetry and the QCD phase diagram
Leonid Ya. Glozman🇦🇹 · Owe Philipsen🇩🇪 · Robert D. Pisarski🇺🇸
Lattice QCD simulations with chirally symmetric quarks have recently established approximate $S U (2)_{C S}$ and $S U (2 N_{F})$ symmetries of the quantum effective action in a temperature range above the chiral crossover $T_{ch}$ , in which color-electric interactions between quarks dominate the dynamics. We show that such an intermediate temperature range between the chirally broken and plasma regimes is fully consistent with published screening mass spectra, which demonstrate the breakdown of thermal perturbation theory at the crossover between the partonic and the chiral spin symmetric regime at $T_{s} \sim (2 - 3) T_{ch}$ . From the known behavior of screening masses with baryon chemical potential, we deduce qualitatively how this chiral spin symmetric band extends into the QCD phase diagram. In the cold and dense region, we propose parity doubled baryons as possible candidates for chiral spin symmetric matter. This represents a special case of quarkyonic matter with confinement and restored chiral symmetry, and can smoothly transform to quark matter at sufficiently high densities. Finally, we discuss the potential of dilepton spectra to identify such matter forms.
Comments:
12 pages, 6 figures, published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2204.05083 [pdf]
EPJA(2022)·59 citations

Affiliations

first authorsco-authorsvia INSPIRE

Isospin dependent properties of the isotopic chain of Scandium and Titanium nuclei within the relativistic mean-field formalism

The optimized point-coupling interaction for the relativistic energy density functional of Hartree-Bogoliubov approach quantifying the nuclear bulk properties

Hyperons, deconfinement and the speed of sound in neutron stars

Neutron-neutral particle mixing and its observable consequences

Spurious poles in a finite volume

Impact of Dynamical Fermions on Centre Vortex Structure

Chiral spin symmetry and the QCD phase diagram

Affiliations