Nuclear Theory·nucl-th

Tuesday·July 22, 2025

17 papers—8 primary·9 cross-listed

09
[Submitted on 18 Jul 2025] (cross-list from hep-ph)
Universal parameters of the $Λ (1380)$ , the $Λ (1405)$ and their isospin partners from a combined analysis of Lattice QCD and experimental results
Ferenc Pittler🇨🇾 · Maxim Mai🇨🇭 · Ulf-G. Meißner🇩🇪 · Ryan F. Ferguson🇬🇧 · Peter Hurck🇬🇧 · David G. Ireland🇬🇧 · Bryan McKinnon🇬🇧
We perform a global analysis of lattice and experimental data on negative-strangeness meson-baryon scattering using a large set of variations of the theoretical framework based on the Chiral Unitary Approach. For the former, the Lüscher formalism is utilized taking into account all pertinent coupled-channel effects. Through this, systematic uncertainties related to data scarcity, potential ambiguities, and possible framework dependence are quantified for the first time. The implementation of information criteria and other statistical tools is discussed. As a final result we provide pole positions for isoscalar resonances at the physical and lattice points including statistical and systematic uncertainties. Predictions for the isovector states are also provided showing large uncertainties.
Comments:
55 pages, 57 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2507.14283 [pdf]
PRD(2025)·11 citations
10
[Submitted on 18 Jul 2025] (cross-list from hep-ph)
Speed of sound peak in isospin QCD: a natural prediction of the Medium Separation Scheme
Bruno S. Lopes🇧🇷 · Dyana C. Duarte🇧🇷 · Ricardo L. S. Farias🇧🇷 · Rudnei O. Ramos🇧🇷
We present predictions for the zero-temperature equation of state at finite isospin density using the Nambu-Jona-Lasinio (NJL) model within the medium separation scheme (MSS) -- a scheme that explicitly disentangles medium effects from the ultraviolet divergent vacuum terms. Recent lattice QCD results reveal a nonmonotonic speed of sound ( $c_{s}^{2}$ ) as a function of isospin chemical potential ( $μ_{I}$ ), exhibiting explicit violation of the conformal bound $c_{s}^{2} = 1/3$ . These findings have attracted significant theoretical interest, as established models -- including the NJL model -- failed to anticipate this behavior prior to lattice simulations. Conventional NJL implementations yield unphysical artifacts, often attributed to regularization scale sensitivity stemming from nonrenormalizability. However, in this work, we demonstrate that the standard NJL framework combined with MSS quantitatively reproduces state-of-the-art lattice data for isospin QCD.
Comments:
8 pages, 4 figures. Updated to match the published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2507.14343 [pdf]
PRD(2025)·15 citations
11
[Submitted on 18 Jul 2025] (cross-list from hep-ph)
Goldstone bosons across thermal phase transitions
Peter Lowdon🇩🇪 · Owe Philipsen🇩🇪
Temperature has a significant effect on the properties of quantum field theories (QFTs) with a spontaneously broken symmetry, in particular on the massless Goldstone bosons that exist in the vacuum state. It has recently been shown using lattice calculations for a $U (1)$ complex scalar field theory that the Goldstone mode persists even when the symmetry is restored above the critical temperature $T_{c}$ , and has the properties of a screened excitation, a so-called thermoparticle. In this work, we continue the investigation of this theory by determining explicitly how the Goldstone mode evolves as the temperature is increased both below and above $T_{c}$ . We find that the two phases of the theory are entirely characterised by the thermal dissipative effects experienced by the Goldstone mode, with the broken and symmetry-restored phases associated with weak and strong damping, respectively. These findings are consistent with the non-perturbative constraints imposed by spontaneous symmetry breaking, and provide a new way in which to characterise thermal phase transitions in QFTs.
Comments:
18 pages, 5 figures; v2: additional discussion added, matches published version. Figure data attached
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2507.14348 [pdf]
JHEP(2026)·4 citations
12
[Submitted on 18 Jul 2025] (cross-list from hep-ph)
On the Impossibility of Obtaining Time-Independent, Three-Dimensional, Spherically-Symmetric Densities of Confined Systems of Relativistically Moving Constituents
Gerald A. Miller🇺🇸
The quantum mechanical definition of probability, the uncertainty principle and Poincare invariance provide strong basic restrictions on the ability to define spatial densities associated with form factors describing the properties of confined systems of relativistically moving constituents. Despite this, many papers ignore one or more of these restrictions. Here I show how to obtain time-independent, two-dimensional densities that are consistent with the stated restrictions. This is done using the light-front, infinite momentum frame formalism. Two-dimensional density interpretations of the axial-vector form factor and all three gravitational form factors are obtained. Additionally, an expression of a two-dimensional mass density related to the trace of the energy momentum tensor is obtained. I also show that all known methods for finding three-dimensional densities: using the Breit frame, Abel transformations, Wigner distributions and spherically-symmetric wave packets with vanishing spatial extent violate the basic restrictions in different manners. Furthermore, the use of the latter leads to densities that vanish almost everywhere in space as time increases from an initial value.
Comments:
16 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2507.14388 [pdf]
PRC(2025)·10 citations
13
[Submitted on 20 Jul 2025] (cross-list from hep-ph)
First Extraction of the $ϕ$ - $^{4} He$ scattering length from near-threshold $ϕ$ photoproduction on helium-4
Chengdong Han🇨🇳 · Wei Kou🇨🇳 · Rong Wang🇨🇳 · Xurong Chen🇨🇳
We present a model-independent extraction of the phi-4He scattering length from near-threshold phi photoproduction on helium-4, based on LEPS Collaboration data for the coherent process gamma + 4He -> phi + 4He and the Vector Meson Dominance framework. Assuming an energy-independent differential cross section, we extract the absolute value of the phi-4He scattering length |alpha_{phi4He}| = (3.33 +- 0.06) x 10^{-4} fm from a fit at threshold t_thr. This value is orders of magnitude smaller than those for phi-N and phi-d scattering lengths, indicating an inverse dependence of |alpha_VA| on the target nucleus mass. Our results provide new insight into the phi-nucleus interaction, supporting the notion of weak phi-nucleus coupling. We further explore the dependence of |alpha_VA| on the vector meson mass, the target atom mass, and the threshold energy. An approximate exponential suppression of |alpha_VA| is observed with increasing vector meson mass or target atom mass, indicating that heavier vector mesons or heavier target nuclei exhibit weaker couplings in vector meson-nucleus interactions.
Comments:
6 pages, 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2507.14972 [pdf]
EPJC(2025)·0 citations
14
[Submitted on 21 Jul 2025] (cross-list from hep-ph)
Is the shear induced spin polarization non-dissipative?
Jia-Rong Wang🇨🇳 · Shuo Fang🇨🇳 · Di-Lun Yang🇹🇼 · Shi Pu🇨🇳
The shear-induced polarization plays a crucial role in understanding the local polarization of $Λ$ and $Λ$ hyperons. A key puzzle is whether the shear-induced polarization is non-dissipative or not. In this work, we analyzed the shear-induced polarization and the anomalous Hall effects using the entropy flow and H-theorem introduced from quantum (chiral) kinetic theory. While the shear-induced polarization and the anomalous Hall effect do not directly contribute to the entropy production rate, the perturbations associated with the shear tensor lead to an increase in entropy, similar to the role of the shear tensor in classical kinetic theory. We also examined these effects within the framework of linear response theory using Zubarev's approach. The analysis of time-reversal transformation on the spin current in coordinate space suggests that shear-induced polarization violates time-reversal symmetry and, therefore, should vanish. However, a similar analysis of the Wigner function in phase space does not impose any additional constraints on shear-induced polarization, allowing it to persist in phase space as expected. This discussion indicates that time-reversal analysis in coordinate space alone may not be sufficient to determine whether an effect is dissipative. Furthermore, our analysis based on Zubarev's approach suggests that these effects may indeed possess a dissipative nature. These findings highlight the limitations of the current theoretical framework in fully characterizing the dissipative properties of these phenomena.
Comments:
19 pages, no figure
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2507.15238 [pdf]
PRD(2026)·5 citations
15
[Submitted on 21 Jul 2025] (cross-list from hep-ph)
Spin correlations and Bell nonlocality in $Λ Λ ˉ$ pair production from $e^{+} e^{-}$ collisions with a thrust cut
Shi-Jia Lin🇨🇳 · Ming-Jun Liu🇨🇳 · Ding Yu Shao🇨🇳 · Shu-Yi Wei🇨🇳
We present a comprehensive theoretical study of spin correlations in $Λ Λ ˉ$ production from $e^{+} e^{-}$ annihilation, providing the theoretical predictions for the Belle II experiment. Using soft-collinear effective theory, we perform the first resummation of large logarithms for the longitudinal ( $C_{LL}$ ) and transverse ( $C_{T T}$ ) spin correlations for events with a cut on the thrust variable. Our calculation achieves next-to-next-to-leading logarithmic accuracy and incorporates the determination of polarized fragmenting jet functions. This framework provides robust predictions with significantly reduced theoretical uncertainties compared to fixed-order parton model approaches. Furthermore, we establish a direct mapping between the experimentally accessible spin correlation, $C_{T T}$ , and a testable CHSH-Bell inequality. This result reframes $C_{T T}$ as a quantitative probe of quantum decoherence, providing a novel tool to measure the degree of parton-level entanglement that survives the fragmentation and hadronization process.
Comments:
32 pages, 5 figures, journal version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2507.15387 [pdf]
JHEP(2025)·31 citations
16
[Submitted on 21 Jul 2025] (cross-list from hep-th)
The role of scalar current coupling along surfaces
F.A. Barone🇧🇷 · L.H.C. Borges🇧🇷 · G. Flores-Hidalgo🇧🇷 · H.L. Oliveira🇧🇷 · W.Y.A. da Silva🇧🇷
In this paper we propose a coupling between the complex scalar field and an external Dirac delta-like planar potential. The coupling is achieved through the Klein-Gordon current normal to the plane where the potential is concentrated. The results are obtained exactly and exhibit many peculiarities. We show that a complex scalar charge does not interact with the potential, but the potential modifies the interaction between two scalar charges if they are placed on opposite sides of the planar potential. When the coupling constant between the potential and the field goes to infinity, the classical field solutions satisfy a kind of MIT boundary conditions along the plane where the potential is concentrated.
Comments:
24 pages, 2 figures
Subjects:
High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2507.15625 [pdf]
EPJC(2024)·5 citations
17
[Submitted on 21 Jul 2025] (cross-list from hep-lat)
TASI/CERN/KITP Lecture Notes on "Toward Quantum Computing Gauge Theories of Nature"
Zohreh Davoudi🇺🇸
A hallmark of the computational campaign in nuclear and particle physics is the lattice-gauge-theory program. It continues to enable theoretical predictions for a range of phenomena in nature from the underlying Standard Model. The emergence of a new computational paradigm based on quantum computing, therefore, can introduce further advances in this program. In particular, it is believed that quantum computing will make possible first-principles studies of matter at extreme densities, and in and out of equilibrium, hence improving our theoretical description of early universe, astrophysical environments, and high-energy particle collisions. Developing and advancing a quantum-computing based lattice-gauge-theory program, therefore, is a vibrant and fast-moving area of research in theoretical nuclear and particle physics. These lecture notes introduce the topic of quantum computing lattice gauge theories in a pedagogical manner, with an emphasis on theoretical and algorithmic aspects of the program, and on the most common approaches and practices, to keep the presentation focused and useful. Hamiltonian formulation of lattice gauge theories is introduced within the Kogut-Susskind framework, the notion of Hilbert space and physical states is discussed, and some elementary numerical methods for performing Hamiltonian simulations are discussed. Quantum-simulation preliminaries and digital quantum-computing basics are presented, which set the stage for concrete examples of gauge-theory quantum-circuit design and resource analysis. A step-by-step analysis is provided for a simpler Abelian gauge theory, and an overview of our current understanding of the quantum-computing cost of quantum chromodynamics is presented in the end. Examples and exercises augment the material, and reinforce the concepts and methods introduced throughout.
Comments:
58 pages, 14 figures, 7 exercises; v2: minor typos fixed
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2507.15840 [pdf]
19 citations

Affiliations

first authorsco-authorsvia INSPIRE