Nuclear Theory·nucl-th

Friday·September 30, 2022

10 papers—2 primary·8 cross-listed

03
[Submitted on 28 Sept 2022] (cross-list from hep-ph)
Symmetry energy in holographic QCD
Lorenzo Bartolini🇨🇳 · Sven Bjarke Gudnason🇨🇳
We study the symmetry energy (SE), an important quantity in nuclear physics, in the Witten-Sakai-Sugimoto model and in a much simpler hard-wall model of holographic QCD. The SE is the energy contribution to the nucleus due to having an unequal number of neutrons and protons. Using a homogeneous Ansatz representing smeared instantons and quantizing their isospin, we extract the SE and the proton fraction assuming charge neutrality and beta-equilibrium, using quantization of the isospin zeromode. We also show the equivalence between our method adapted from solitons and the usual way of the isospin controlled by a chemical potential at the holographic boundary. We find that the SE can be well described in the WSS model if we allow for a larger 't Hooft coupling and lower Kaluza-Klein scale than is normally used in phenomenological fits.
Comments:
LaTeX: 29 pages, 5 figures; V2: extended version; V3: comments, references and appendices C through E added
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2209.14309 [pdf]
SciPost Phys.(2024)·19 citations
04
[Submitted on 28 Sept 2022] (cross-list from hep-ph)
Three-loop corrections to the quark and gluon decomposition of the QCD trace anomaly and their applications
Kazuhiro Tanaka (Juntendo Univ.)🇯🇵
In the QCD energy-momentum tensor $T^{μν}$ , the terms that contribute to physical matrix elements are expressed as the sum of the gauge-invariant quark part and gluon part. Each part undergoes the renormalization due to the interactions among quarks and gluons, although the total tensor $T^{μν}$ is not renormalized thanks to conservation of energy and momentum. We show that, through the renormalization, each of the quark and gluon parts of $T^{μν}$ receives a definite amount of anomalous trace contribution, such that their sum reproduces the well-known QCD trace anomaly. We provide a procedure to derive such anomalous trace contribution for each quark/gluon part to all orders in perturbation theory, and obtain the corresponding explicit formulas up to three-loop order in the $MS$ scheme in the dimensional regularization. We apply our three-loop formulas of the quark/gluon decomposition of the trace anomaly to calculate the anomaly-induced mass structure of nucleons as well as pions. Another application of our three-loop formulas is a quantitative analysis for the constraints on the twist-four gravitational form factors of the nucleon, $C ˉ_{q, g}$ .
Comments:
5 pages, 2 figures. Contribution to the 24th International Spin Symposium (SPIN2021). JPS Conference Proceedings
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2209.14367 [pdf]
JPS Conf.Proc.(2022)·5 citations
05
[Submitted on 28 Sept 2022] (cross-list from nucl-ex)
Searching for an Enhanced Signal of the onset of Color Transparency in Baryons with D(e,e'p)n scattering
Shujie Li🇺🇸 · Carlos Yero🇺🇸 · Jennifer Rittenhouse West🇺🇸 · Clare Bennett🇺🇸 · Wim Cosyn🇺🇸 · Douglas Higinbotham🇺🇸 · Misak Sargsian🇺🇸 · Holly Szumila-Vance🇺🇸
Observation of the onset of color transparency in baryons would provide a new means of studying the nuclear strong force and would be the first clear evidence of baryons transforming into a color-neutral point-like size in the nucleus as predicted by quantum chromodynamics. Recent C $(e, e^{'} p)$ results from electron-scattering did not observe the onset of color transparency (CT) in protons up to spacelike four-momentum transfers squared, $Q^{2} = 14.2$ GeV $^{2}$ . The traditional methods of searching for CT in $(e, e^{'} p)$ scattering use heavy targets favoring kinematics with already initially reduced final state interactions (FSIs) such that any CT effect that further reduces FSIs will be small. The reasoning behind this choice is the difficulty in accounting for all FSIs. D $(e, e^{'} p) n$ , on the other hand, has well-understood FSI contributions from double scattering with a known dependence on the kinematics and can show an increased sensitivity to hadrons in point-like configurations. Double scattering is the square of the re-scattering amplitude in which the knocked-out nucleon interacts with the spectator nucleon, a process that is suppressed in the presence of point-like configurations and is particularly well-studied for the deuteron. This suppression yields a quadratic sensitivity to CT effects and is strongly dependent on the choice of kinematics. Here, we describe a possible JLab electron-scattering experiment that utilizes these kinematics and explores the potential signal for the onset of CT with enhanced sensitivity as compared to recent experiments.
Comments:
14 pages
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2209.14400 [pdf]
MDPI Physics(2022)·7 citations
06
[Submitted on 29 Sept 2022] (cross-list from hep-ph)
Statistical hadronization of b-quarks in Pb-Pb collisions at LHC energy: a case for partial equilibration of b-quarks?
A. Andronic🇩🇪 · P. Braun-Munzinger🇩🇪 · K. Redlich🇵🇱 · J. Stachel🇩🇪
Predictions are presented within the framework of the statistical hadronization model for integrated yields of bottomonia in Pb-Pb collisions at the LHC. We investigate the centrality dependence of $Υ$ production and provide predictions for a large set of still-unmeasured open-beauty hadrons.
Comments:
6 pages, 3 figures; proceedings of Quark Matter 2022
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2209.14562 [pdf]
Acta Phys.Polon.Supp.(2023)·9 citations
07
[Submitted on 29 Sept 2022] (cross-list from hep-lat)
Open charm mesons at nonzero temperature: results in the hadronic phase from lattice QCD
Gert Aarts🇬🇧 · Chris Allton🇬🇧 · Ryan Bignell🇬🇧 · Timothy J. Burns🇬🇧 · Sergio Chaves García-Mascaraque🇬🇧 · Simon Hands🇬🇧 · Benjamin Jäger🇩🇰 · Seyong Kim🇰🇷 · Sinéad M. Ryan🇮🇪 · Jon-Ivar Skullerud🇮🇪
We study what happens to D and D_s mesons as the temperature increases, using lattice QCD simulations with N_f=2+1 dynamical flavours on anistropic lattices. We have access to five temperatures in the hadronic phase. Using the determined groundstate mass at the lowest temperature, we investigate the effect of rising temperature by analysing ratios of mesonic correlators, without the need for further fitting or spectral reconstruction. In the pseudoscalar and vector channels, we demonstrate that temperature effects are at the percent level and can be captured by a reduction of the groundstate mass as the thermal crossover is approached. In the axial-vector and scalar channels on the other hand, temperature effects are prominent throughout the hadronic phase.
Comments:
35 pages, 25 pdf figures
Subjects:
High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2209.14681 [pdf]
37 citations
08
[Submitted on 29 Sept 2022] (cross-list from hep-ph)
Solar neutrino physics
Xun-Jie Xu🇨🇳 · Zhe Wang🇨🇳 · Shaomin Chen🇨🇳
As a free, intensive, weakly interacting, and well directional messenger, solar neutrinos have been driving both solar physics and neutrino physics developments for more than half a century. Since more extensive and advanced neutrino experiments are under construction, being planned or proposed, we are striving toward an era of precise and comprehensive measurement of solar neutrinos in the next decades. In this article, we review recent theoretical and experimental progress achieved in solar neutrino physics. We present not only an introduction to neutrinos from the standard solar model and the standard flavor evolution, but also a compilation of a variety of new physics that could affect and hence be probed by solar neutrinos. After reviewing the latest techniques and issues involved in the measurement of solar neutrino spectra and background reduction, we provide our anticipation on the physics gains from the new generation of neutrino experiments.
Comments:
75 pages, 25 figures, fixed a typo in Fig. 2.1
Subjects:
High Energy Physics — Phenomenology (hep-ph); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2209.14832 [pdf]
PPNP(2023)·44 citations
09
[Submitted on 29 Sept 2022] (cross-list from hep-ph)
Precision QCD, Hadronic Structure & Forward QCD, Heavy Ions: Report of Energy Frontier Topical Groups 5, 6, 7 submitted to Snowmass 2021
M. Begel · S. Hoeche · M. Schmitt · H.-W. Lin · P.M. Nadolsky · C. Royon · Y-J. Lee · S. Mukherjee · C. Baldenegro · J. Campbell · G. Chachamis · F.G. Celiberto and 38 other authors
This report was prepared on behalf of three Energy Frontier Topical Groups of the Snowmass 2021 Community Planning Exercise. It summarizes the status and implications of studies of strong interactions in high-energy experiments and QCD theory. We emphasize the rich landscape and broad impact of these studies in the decade ahead. Hadronic interactions play a central role in the high-luminosity Large Hadron Collider (LHC) physics program, and strong synergies exist between the (HL-)LHC and planned or proposed experiments at the U.S. Electron-Ion Collider, CERN forward physics experiments, high-intensity facilities, and future TeV-range lepton and hadron colliders. Prospects for precision determinations of the strong coupling and a variety of nonperturbative distribution and fragmentation functions are examined. We also review the potential of envisioned tests of new dynamical regimes of QCD in high-energy and high-density scattering processes with nucleon, ion, and photon initial states. The important role of the high-energy heavy-ion program in studies of nuclear structure and the nuclear medium, and its connections with QCD involving nucleons are summarized. We address ongoing and future theoretical advancements in multi-loop QCD computations, lattice QCD, jet substructure, and event generators. Cross-cutting connections between experimental measurements, theoretical predictions, large-scale data analysis, and high-performance computing are emphasized.
Comments:
95 pages (bibliography 30 pages), 28 figures; v.2: minor changes, authors and references added
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2209.14872 [pdf]
35 citations
10
[Submitted on 29 Sept 2022] (cross-list from hep-th)
Non-Gaussian Fluctuation Dynamics
Xin An🇺🇸
Recent progress of a general deterministic approach to the non-Gaussian fluctuation dynamics is reviewed, with an emphasis on the derivation of the fluctuation evolution equations and their phenomenological implication in heavy-ion collision experiments.
Comments:
6 pages, 5 figures. Contribution to the XXIXth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions (Quark Matter 2022)
Subjects:
High Energy Physics — Theory (hep-th); Statistical Mechanics (cond-mat.stat-mech); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2209.15005 [pdf]
Acta Phys.Polon.Supp.(2023)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE