Nuclear Theory·nucl-th

Thursday·September 8, 2022

11 papers—5 primary·6 cross-listed

06
[Submitted on 6 Sept 2022] (cross-list from astro-ph.HE)
Deducing Neutron Star Equation of State Parameters Directly From Telescope Spectra with Uncertainty-Aware Machine Learning
Delaney Farrell🇺🇸 · Pierre Baldi🇺🇸 · Jordan Ott🇺🇸 · Aishik Ghosh🇺🇸 · Andrew W. Steiner🇺🇸 · Atharva Kavitkar🇩🇪 · Lee Lindblom🇺🇸 · Daniel Whiteson🇺🇸 · Fridolin Weber🇺🇸
Neutron stars provide a unique laboratory for studying matter at extreme pressures and densities. While there is no direct way to explore their interior structure, X-rays emitted from these stars can indirectly provide clues to the equation of state (EOS) of superdense nuclear matter through the inference of the star's mass and radius. However, inference of EOS directly from a star's X-ray spectra is extremely challenging and is complicated by systematic uncertainties. The current state of the art is to use simulation-based likelihoods in a piece-wise method, which first infer the star's mass and radius to reduce the dimensionality of the problem, and from those quantities infer the EOS. We demonstrate a series of enhancements to the state of the art, in terms of realistic uncertainty quantification and improved regression of physical properties with machine learning. We also demonstrate novel inference of the EOS directly from the high-dimensional spectra of observed stars, avoiding the intermediate mass-radius step. Our network is conditioned on the sources of uncertainty of each star, allowing for natural and complete propagation of uncertainties to the EOS.
Comments:
24 pages, 20 figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
arXiv:
2209.02817 [pdf]
JCAP(2023)·19 citations
07
[Submitted on 6 Sept 2022] (cross-list from hep-th)
Denominator Regularization in Quantum Field Theory
W. A. Horowitz🇿🇦
We propose a novel regularization scheme in quantum field theory, denominator regularization (den reg). As simple to apply as dimensional regularization, and similarly compatible with a minimal subtraction renormalization scheme, den reg manifestly 1) maintains Lorentz invariance, 2) maintains gauge invariance, 3) maintains supersymmetry, 4) correctly predicts the axial anomaly, and 5) yields Green functions that satisfy the Callan-Symanzik equation. Den reg also naturally enables regularization in asymmetric spacetimes, finite spacetimes, curved spacetimes, and in thermal field theory.
Comments:
6 pages
Subjects:
High Energy Physics — Theory (hep-th); Statistical Mechanics (cond-mat.stat-mech); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2209.02820 [pdf]
8 citations
08
[Submitted on 7 Sept 2022] (cross-list from hep-ph)
Tetraquark mixing supported by the partial decay widths of two light-meson nonets
Hungchong Kim🇰🇷 · K. S. Kim🇰🇷
Recently, the tetraquark mixing framework has been proposed as a possible structure for the two light-meson nonets in the $J^{P} = 0^{+}$ channel, the light nonet composed of $a_{0} (980)$ , $K_{0}^{*} (700)$ , $f_{0} (500)$ , $f_{0} (980)$ , and the heavy nonet of $a_{0} (1450)$ , $K_{0}^{*} (1430)$ , $f_{0} (1370)$ , $f_{0} (1500)$ . Among various signatures, we report in this work that their partial decay widths collected from various experimental data in Particle Data Group (PDG) can support this mixing scheme also. In particular, we demonstrate that the couplings of the light nonet to two pseudoscalar mesons estimated from the partial widths are consistently stronger than those of the heavy nonet. This consistent feature agrees qualitatively well with the predictions from the tetraquark mixing framework and, therefore, provides supporting evidence for the tetraquark mixing.
Comments:
Substantially revised. 9 pages, no figures. Accepted for publication in EPJC
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2209.02958 [pdf]
EPJC(2022)·7 citations
09
[Submitted on 7 Sept 2022] (cross-list from hep-ph)
Particle species and energy dependencies of freeze-out parameters in high-energy proton-proton collisions
Muhammad Waqas🇨🇳 · Guang Xiong Peng🇨🇳 · Fu-Hu Liu🇨🇳 · Muhammad Ajaz🇵🇰 · Abd Al Karim Haj Ismail🇦🇪 · Khusniddin K. Olimov🇺🇿 · Abdel Nasser Tawfik🇪🇬
We used blast wave model with Tsallis statistics to analyze the experimental data measured by ALICE Collaboration in proton-proton collisions at Large Hadron Collider and extracted the related parameters (kinetic freeze-out temperature, transverse flow velocity and kinetic freeze-out volume of emission source) from transverse momentum spectra of the particles. We found that the kinetic freeze-out temperature and kinetic freeze-out volume are mass dependent. The former increase while the latter decrease with the particle mass which is the evidence of a mass as well as volume differential kinetic freeze-out scenario. Furthermore we extracted the mean transverse momentum and initial temperature by an indirect method and observed that they increase with mass of the particles. All the above discussed parameters are observed to increase with energy. Triton ( $t$ ), hyper-triton ( $_{Λ ˉ}^{3} H$ ) and helion ( $^{3} H e$ ) and their anti-matter are observed to freeze-out at the same time due to isospin symmetry.
Comments:
13 pages, 5 figures, 1 table
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2209.03030 [pdf]
Eur.Phys.J.Plus(2022)·6 citations
10
[Submitted on 7 Sept 2022] (cross-list from gr-qc)
Neutron Star Crust Can Support A Large Ellipticity
J. A. Morales🇺🇸 · C. J. Horowitz🇺🇸
Non-axisymmetrical deformations of the crust on rapidly rotating neutron stars are one of the main targets of searches for continuous gravitational waves. The maximum ellipticity, or fractional difference in moments of inertia, that can be supported by deformations of the crust (known as "mountains") provides an important upper limit on the strength of these continuous gravitational wave sources. We use the formalism of Gittins et al 2021, along with a deforming force that acts mainly in the transverse direction, to obtain a maximum ellipticity of 7.4 $\times$ 10 $^{- 6}$ . This is larger than the original results of Gittins et al 2021 but consistent with earlier calculations by Ushomirsky et al 2000. This suggests that rotating neutron stars could be strong sources of continuous gravitational waves.
Comments:
9 pages, 5 figures, minor revisions MNRAS in press
Subjects:
General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2209.03222 [pdf]
MNRAS(2022)·52 citations
11
[Submitted on 7 Sept 2022] (cross-list from hep-ph)
Report of the Topical Group on Neutrino Properties for Snowmass 2021
Carlo Giunti🇮🇹 · Julieta Gruszko🇺🇸 · Benjamin Jones🇺🇸 · Lisa Kaufman🇺🇸 · Diana Parno🇺🇸 · Andrea Pocar🇺🇸
Neutrinos are the most elusive among the known elementary particles, because of their feeble interactions with ordinary matter. They are also the most mysterious, because of their tiny masses that suggest a novel mass generating mechanism, their unknown Dirac or Majorana nature, and their big quantum mixing leading to large-amplitude flavor oscillations. This Topical Group focuses on neutrino properties that are not directly investigated in other Topical Groups of the Neutrino Frontier: in particular, the absolute value of the neutrino masses, the Dirac or Majorana nature of neutrinos, their electromagnetic properties, their lifetime, and hypothetical exotic properties.
Comments:
Topical Group Report for NF05 (Neutrino Frontier Topical Group on Neutrino Properties) for Snowmass 2021. 51 pages excluding references
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2209.03340 [pdf]
15 citations

Affiliations

first authorsco-authorsvia INSPIRE

Deducing Neutron Star Equation of State Parameters Directly From Telescope Spectra with Uncertainty-Aware Machine Learning

Denominator Regularization in Quantum Field Theory

Tetraquark mixing supported by the partial decay widths of two light-meson nonets

Particle species and energy dependencies of freeze-out parameters in high-energy proton-proton collisions

Neutron Star Crust Can Support A Large Ellipticity

Report of the Topical Group on Neutrino Properties for Snowmass 2021

Affiliations