Nuclear Theory·nucl-th

Friday·February 14, 2025

9 papers—5 primary·4 cross-listed

01
[Submitted on 12 Feb 2025]
Causality constraints on radiative transfer
Lorenzo Gavassino🇺🇸
The standard formula, due to Spiegel, for the smoothing of temperature fluctuations by radiative transfer is unstable in relativity. This is due to the fact that Spiegel neglected the transit time of light, thereby allowing the transport coefficients to move outside the convex geometry compatible with causality (the "hydrohedron"). Here, we fix this pathology. First, we prove that the linearized radiative transfer equations are causal and covariantly stable by construction. Then, we repeat Spiegel's calculation accounting for the finite speed of photons. We find that the full transfer problem can be solved analytically. All the infinite (exact) transport coefficients arising from it fall inside the hydrohedron. Our analysis also accounts for isotropic scattering.
Comments:
11 pages, 4 figure, published on PRD (see https://journals.aps.org/prd/abstract/10.1103/PhysRevD.111.103011)
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Theory (hep-th)
arXiv:
2502.08740 [pdf]
PRD(2025)·4 citations
02
[Submitted on 13 Feb 2025]
Bose-Einstein condensation of five $α$ clusters in $^{20}$ Ne and supersolidity
S. Ohkubo · J. Takahashi · Y. Yamanaka
We show that the five $α$ cluster states recently observed in $^{20}$ Ne, slightly above the five $α$ threshold energy, are Bose-Einstein condensates of five $α$ clusters. The states are described well using a superfluid cluster model, where the order parameter is defined. We suggest that the the five $α$ states are fragmented. Theory predicts the emergence of a five $α$ rotational roton band characterized by a large moment of inertia. This band is formed through roton excitations of the five $α$ BEC vacuum and possesses dual properties of superfluidity and crystallinity, a property of supersolidity. The persistent existence of such a roton bandis discussed and confirmed for the four $α$ condensate above the four $α$ threshold in $^{16}$ O and the three $α$ condensate above the three $α$ threshold in $^{12}$ C.
Comments:
8pages, 5figures
Subjects:
Nuclear Theory (nucl-th); Quantum Gases (cond-mat.quant-gas); Nuclear Experiment (nucl-ex)
arXiv:
2502.08901 [pdf]
Eur.Phys.J.Plus(2025)·1 citation
03
[Submitted on 13 Feb 2025]
Quarkonium Spectroscopy in the Quark-Gluon Plasma
Zhanduo Tang🇺🇸 · Biaogang Wu🇺🇸 · Andrew Hanlon🇺🇸 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Ralf Rapp🇺🇸
The properties of bound states are fundamental to hadronic spectroscopy and play a central role in the transition from hadronic matter to a quark-gluon plasma (QGP). In a strongly coupled QGP (sQGP), the interplay of temperature, binding energy and large collisional widths of the partons poses formidable challenges in evaluating the in-medium properties of hadronic states and their eventual melting. In particular, the existence of heavy quarkonia in the QGP is a long-standing problem that is hard to solve by considering their spectral properties on the real-energy axis. We address this problem by analyzing in-medium thermodynamic quarkonium $T$ -matrices in the complex energy plane. We first validate this method in vacuum, where the $T$ -matrix poles of observed states are readily identified. When deploying this approach to recent self-consistently calculated $T$ -matrices in the QGP, we find that poles in the complex energy plane can persist to surprisingly large temperatures, depending on the strength of the in-medium interactions. While the masses and widths of the pole positions are precisely defined, the notion of a binding energy is not due to the absence of thresholds caused by the (large) widths of the underlying anti-/quark spectral functions. Our method thus provides a new and definitive quantum-mechanical criterion to determine the melting temperature of hadronic states in the sQGP while increasing the accuracy in the theoretical determination of transport parameters.
Comments:
6 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2502.09044 [pdf]
PRL(2025)·13 citations
04
[Submitted on 13 Feb 2025]
Low-energy spectra of nobelium isotopes: Skyrme random-phase-approximation analysis
V. O. Nesterenko · M. A. Mardyban · A. Repko · R. V. Jolos · P.-G. Reinhard · Alan A. Dzhioev
Low-energy spectra in the isotopic chain $^{250 - 262}$ No are systematically investigated within the fully self-consistent Quasiparticle Random-Phase-Approximation (QRPA) using Skyrme forces SLy4, SLy6, SkM* and SVbas. QRPA states of multipolarity $λ μ$ =20, 22, 30, 31, 32, 33, 43, 44 and 98 are considered. The main attention is paid to isotopes $^{252}$ No and $^{254}$ No where the most extensive experimental spectroscopic information is available. In these two nuclei, a reasonable description of $K^{π} = 8^{-}, 2^{-}$ and $3^{+}$ isomers is obtained with forces SLy4 and SLy6. The disputed $8^{-}$ isomer in $^{254}$ No is assigned as neutron two-quasiparticle configuration $nn [734 ↑, 613 ↑]$ . The isomers are additionally analyzed using Skyrme functionals UNEDF1, UNEDF2 and UNEDF1 $^{SO}$ . At the energies 1.2 - 1.4 MeV, the 2qp $K$ -isomers $4^{-}, 7^{-}$ in $^{252}$ No and $4^{-}, 6^{-}, 7^{-}$ in $^{254}$ No are also predicted. In $^{254}$ No, the $K^{π} = 3^{+}$ isomer should be accompanied by the nearby $K^{π} = 4^{+}$ counterpart. It is shown that, in the chain $^{250 - 262}$ No, some features of $^{252}$ No and $^{254}$ No should exhibit essential irregularities caused by a noticeable shell gap in the neutron single-particle spectrum and corresponding reduction of the neutron pairing. In particular, low-energy pairing-vibrational $K^{π} = 0^{+}$ states in $^{252, 254}$ No are predicted.
Comments:
The version published in Phys. Rev. C 111, 064322 (2025). 19 pages, 14 tables, 7 figures. As compared with the previous arXiv version, the missprints in the text and some figures were corrected
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2502.09096 [pdf]
PRC(2025)·2 citations
05
[Submitted on 13 Feb 2025]
Source function from two-particle correlation function through entropy-regularized Richardson-Lucy deblurring
C. K. Tam · Z. Chajęcki · P. Danielewicz · P. Nzabahimana
Source functions are obtained from $p$ - $p$ and $d$ -- $α$ correlation functions by applying the Richardson-Lucy (RL) deblurring to the Koonin-Pratt (KP) equation. To prevent fitting of noise in the correlation function, total-variation (TV) regularization is employed that has been effective in ordinary image restoration. TV alone cannot ensure normalization of the source functions. To ensure the latter, we propose a maximum-entropy regularized RL algorithm (MEM-RL). We outline the MEM-RL formalism and optimization strategy for the KP equation, demonstrating its effectiveness on both simulated and experimental data, including the $p$ - $p$ and $d$ - $α$ correlation functions.
Comments:
22 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2502.09478 [pdf]
PRC(2025)·9 citations
06
[Submitted on 12 Feb 2025] (cross-list from hep-ph)
Revisiting Gauge Ambiguities for DUNE Precision
Joshua Isaacson🇺🇸
The de Forest prescription for handling off-shell initial states in the impulse approximation for lepton-nucleus scattering breaks gauge invariance. We discuss existing methods to address this problem and handle the form factor scale ambiguity. We demonstrate that the irreducible differences between the prescriptions are significant compared to the precision expected of next-generation accelerator neutrino experiments. A novel approach directly using the off-shell currents is proposed as a systematically improvable alternative.
Comments:
5 pages, 3 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2502.08727 [pdf]
1 citation
07
[Submitted on 12 Feb 2025] (cross-list from hep-lat)
Internal color contributions to flux tube entanglement entropy
Rocco Amorosso🇺🇸 · Sergey Syritsyn🇺🇸 · Raju Venugopalan🇺🇸
In recent work arXiv:2410.00112, we introduced and computed entanglement entropy of the color flux tube (FTE $^{2}$ ) between a heavy quark-antiquark pair in (2+1)D Yang-Mills theory. Our numerical results suggest that FTE $^{2}$ can be partitioned into a component corresponding to transverse vibrations of the flux tube and an internal color entropy. Further, motivated by analytical (1+1)D calculations, and SU(2) (2+1)D Yang-Mills numerical results, we argued that the internal entropy takes the form $⟨ F ⟩ lo g (N_{c})$ , with $⟨ F ⟩$ the number of times, on average, that the flux tube crossed a boundary between region $V$ and its complement. We extend here our FTE $^{2}$ study to consider different geometries of region $V$ , varying the number of boundary crossings, and number of colors. Our preliminary results support the conjectured form of the internal entropy, albeit with noteworthy subtleties relating to the partial/full intersections of the flux tube with the region $V$ .
Comments:
11 pages, 6 figures. arXiv admin note: text overlap with arXiv:2410.00112
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2502.08737 [pdf]
PoS(2025)·4 citations
08
[Submitted on 13 Feb 2025] (cross-list from astro-ph.HE)
PSR J1231-1411 revisited: Pulse Profile Analysis of X-ray Observation
Liqiang Qi · Shijie Zheng · Juan Zhang · Mingyu Ge · Ang Li · Shuang-Nan Zhang · Fang-Jun Lu · Han-Long Peng · Liang Zhang · Hua Feng · Zhen Zhang · Yupeng Xu and 5 other authors
One of the primary goals of Neutron Star Interior Composition Explorer (NICER)-like X-ray missions is to impose stringent constraints on the neutron star equation of state by precisely measuring their masses and radii. NICER has recently expanded the dataset of inferred mass-radius relations for neutron stars, including four rotation-powered millisecond pulsars PSR J0030+0451, PSR J0740+6620, PSR J0437-4715, and PSR J1231-1411. In this work, the mass-radius relation and X-ray emitting region properties of PSR J1231-1411 are inferred with an independent pulse profile modeling based on the spherical star Schwarzschild-spacetime and Doppler approximation. With one single-temperature elongated hot spot and one single-temperature crescent hot spot, the inferred gravitational mass is $M = 1.12 \pm 0.07 M_{⊙}$ and the inferred equatorial radius is $R_{e q} = 9.9 1_{- 0.86}^{+ 0.88}$ km (68% credible intervals). It provides an alternative geometry configuration of the X-ray emitting region for PSR J1231-1411 to sufficiently explain the observation data of NICER and XMM-Newton. The inferred radius is smaller than that derived by \citet{salmi2024nicer} ( $M = 1.0 4_{- 0.03}^{+ 0.05} M_{⊙}$ , $R_{e q} = 12.6 \pm 0.3$ km), and the inferred mass is slightly higher in this work. The inferred geometry configurations of the X-ray emitting region in both works are non-antipodal, which is not consistent with a centered dipole magnetic field and suggests a complex magnetic field structure.
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2502.09147 [pdf]
ApJ(2025)·26 citations
09
[Submitted on 13 Feb 2025] (cross-list from astro-ph.HE)
PSR J0952-0607: Probing the Stiffest Equations of State and r-Mode Suppression Mechanisms
Zeyue Wu · Bhaskar Biswas · Stephan Rosswog
We analyze PSR J0952-0607, the most massive and fastest spinning neutron star observed to date, to refine constraints on the neutron star equation of state (EoS) and investigate its robustness against r-mode instabilities. With a mass of $ 2.35 \pm 0.17 \, M_{\odot} $ and a spin frequency of 709.2 Hz, PSR J0952-0607 provides a unique opportunity to examine the effects of rapid rotation on the structure of a neutron star. Using a Bayesian framework, we incorporate the rotationally corrected mass of PSR J0952-0607, alongside PSR J0740+6620's static mass measurement, to constrain the EoS. Our findings demonstrate that neglecting rotational effects leads to biases in the inferred EoS, while including the neutron star spin produces tighter constraints on pressure-density and mass-radius relations. Additionally, we explore the r-mode instability window for PSR J0952-0607 under the assumption of both rigid and elastic crust models and find that a rigid crust allows a higher stable temperature range, whereas an elastic crust places the star within the instability window under certain thermal insulation conditions.
Comments:
9 pages, 6 figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2502.09200 [pdf]
5 citations

Affiliations

first authorsco-authorsvia INSPIRE