Nuclear Theory·nucl-th

Tuesday·August 4, 2026

23 papers—15 primary·8 cross-listed

16
[Submitted on 16 Mar 2026] (cross-list from hep-ph)
Effects of equilibrium coexisting phases in the first-order chiral transition within the Linear sigma model with quarks
R. M. Aguirre🇦🇷
The first order chiral phase transition for quark matter with flavor imbalance is studied using the Linear sigma model with quarks, also known as Quark-meson model. Special attention is paid to the role of the scalar isovector meson. The general consensus presently is that the chiral transition changes from a smooth crossover to first-order at low temperatures. This transition is assumed to be discontinuous, with unstable or metastable intermediate states. However, if multiple charges are simultaneously conserved the system could undergo a continuous change through a coexistence of equilibrium states. Under such assumption the bulk properties are analyzed and several remarkable effects for the speed of sound and the susceptibilities are stressed.
Comments:
14pages, 10 figures. Accepted for publication in Physical Review C
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2603.15429 [pdf]
PRC(2026)·0 citations
17
[Submitted on 31 Jul 2026] (cross-list from hep-ph)
Testing Lepton Wave Function Factorization in $^{71} Ge$ Electron Capture
M. Cadeddu🇮🇹 · N. Cargioli🇮🇹 · M. Cau🇮🇹 · F. Dordei🇮🇹 · L. Ferro🇮🇹
Electron-capture ratios provide precision tests of atomic wave functions and of possible non-factorization effects in nuclear electron capture. By exploiting exact leptonic wave functions, we present a general framework for predicting the electron capture rates of $^{71} Ge$ . Adopting a non-factorized treatment of the transition matrix element, we investigate the interplay between the nuclear transition density, which encodes the nuclear structure contribution, and the leptonic wave functions. Using phenomenologically constrained transition densities, we quantify the impact of non-factorization effects on the capture rates. Finally, we compare our theoretical predictions for the $L / K$ , $M / K$ and $M / L$ electron capture ratios with the current experimental world averages, providing an up-to-date assessment of the theoretical and experimental status of $^{71} Ge$ electron capture.
Comments:
9 pages, 2 figures, 4 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2608.00120 [pdf]
0 citations
18
[Submitted on 2 Aug 2026] (cross-list from hep-ph)
Misconceptions About the Physics of the QCD Trace Anomaly from Renormalization in a Reducible Basis
Chen Yang🇺🇸
The QCD trace anomaly is a well-established textbook result in quantum field theory with several prominent features: (1) it arises from the quantum breaking of scale symmetry at ultraviolet (UV) scales, yet is independent of the particular UV regulator used, whether lattice or dimensional regularization; (2) although it is nominally proportional to ( $O (α_{s})$ ), it is free of renormalization-scheme ambiguity; and (3) it is free of UV divergences and is therefore scale independent. Unfortunately, these important features have been undermined in the recently introduced reducible-basis renormalization, leading to misunderstandings of anomaly-related nucleon physics, including the origins of nucleon mass and internal forces.
Comments:
5 pages
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2608.01002 [pdf]
0 citations
19
[Submitted on 2 Aug 2026] (cross-list from hep-ph)
Model analysis on the effectiveness of the HAL QCD method for hadron-hadron interactions
Takayasu Sekihara🇯🇵 · Kei Fujiwara🇯🇵
The HAL QCD method has been one of the powerful tools to extract hadron-hadron interactions directly from lattice QCD simulation data. In this paper, we aim at examining the effectiveness of the HAL QCD method by deriving a formula to calculate quantities in the HAL QCD method, such as the so-called R-correlators and HAL QCD local potentials, from the hadron-hadron scattering amplitudes within effective models. In this framework, we can judge whether the HAL QCD local potential, evaluated in the present formula, reproduces the properties of the original hadron-hadron interaction or not via the scattering amplitude, which is a solution of the Lippmann--Schwinger equation with the original hadron-hadron interaction as an input. In an analysis within a simple model of elastic scattering, we show that, when the original interaction is predominantly local, the HAL QCD local potentials quantitatively reproduce phase shifts of the hadron-hadron scatterings and correctly indicate the existence/absence of the bound state with its binding energy $\sim$ MeV. Lattice discretization of spacetime modifies the results only slightly. Furthermore, we consider the $K ˉ N$ potential in a bare to $K ˉ N$ transition amplitude, which shows singular behavior around the origin in the recent HAL QCD results of the lattice QCD simulation data, and discuss the cause of such singular behavior in the HAL QCD method through our model analysis of the $K ˉ N$ scattering.
Comments:
23 pages, 16 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2608.01225 [pdf]
0 citations
20
[Submitted on 2 Aug 2026] (cross-list from hep-ph)
A femtoscopic tale of two $C$ -parities: the $Z_{c} (3900)$ and the isovector partner of the $X (3872)$
Pan-Pan Shi🇪🇸 · Miguel Albaladejo🇪🇸 · Feng-Kun Guo🇨🇳 · Juan Nieves🇪🇸
Understanding the nature of the exotic $Z_{c} (3900)$ and $Z_{cs} (3985)$ states, and searching for the predicted isovector partner $W_{c 1}$ of the $X (3872)$ , remain central challenges in exotic-hadron spectroscopy. We investigate the femtoscopic correlation functions (CFs) of the $D^{(*) 0} D_{(s)}^{(*) -}$ systems. Since these charm-meson--antimeson pairs are not $G$ -parity eigenstates, their CFs contain contributions from both the $C$ -odd and $C$ -even sectors, providing direct access to the dynamics underlying the $Z_{c}$ , $Z_{cs}$ , and the predicted isovector exotic $W_{c 1}$ . Within a heavy-quark-spin-symmetric coupled-channel framework, we show that the $C$ -even admixture enhances the low-momentum CFs by more than $2.5 σ$ in the vicinity of their thresholds. Free from Coulomb distortions and accessible in high-multiplicity $pp$ collisions at the LHC, these channels offer the first direct femtoscopic probe of the isovector $C$ -even sector and of the elusive $W_{c 1}$ state.
Comments:
14 pages, 8 fugyres
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2608.01237 [pdf]
0 citations
21
[Submitted on 2 Aug 2026] (cross-list from hep-ph)
Properties of the $D_{s 0}^{*} (2317)^{\pm}$ in hot and dense nuclear matter
Tomona Kinugawa🇯🇵 · Àngels Ramos🇪🇸 · Laura Tolos🇪🇸
We investigate the properties of the $D_{s 0}^{*} (2317)^{\pm}$ in hot and dense nuclear matter using a coupled-channel molecular model built on next-to-leading-order heavy meson chiral perturbation theory. In-medium modifications to the $D_{s 0}^{*} (2317)^{+}$ stem from changes to the $D K$ channel within the coupled $D K$ - $D_{s} η$ system. As nuclear density increases, the $D_{s 0}^{*} (2317)^{+}$ quasiparticle peak shifts toward lower energies and broadens, tracking the behavior of the $D$ -meson spectral function. As for temperature effects, those are milder, with the thermal smearing of the Fermi surface and the melting of $Σ_{c} N^{- 1}$ excitations in the $D$ -meson spectral function shifting the $D_{s 0}^{*} (2317)^{+}$ peak back toward its free-space mass while narrowing it. Conversely, the behavior of the $D_{s 0}^{*} (2317)^{-}$ is governed by the $D ˉ K ˉ$ channel and its medium behavior is driven by the $K ˉ$ spectral function. With increasing temperature, the $D_{s 0}^{*} (2317)^{-}$ also approaches its free-space mass, but its width broadens before saturating at high temperatures. Incorporating explicit medium dependencies into the interaction kernel, driven by density and/or temperature variations in the pion decay constant, further shifts the $D_{s 0}^{*} (2317)^{+}$ mass lower and narrows its width with temperature. As for $D_{s 0}^{*} (2317)^{-}$ , its mass also drops with temperature but its width increases. These contrasting medium behaviors offer a promising pathway to constrain the internal structure of these exotic states.
Comments:
16 pages, 10 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2608.01272 [pdf]
0 citations
22
[Submitted on 2 Aug 2026] (cross-list from hep-ph)
What are the consequences of independent factorization and renormalization scales?
T.C. Rogers🇺🇸 · R.M. Whitehill🇺🇸
It is common for separate factorization and renormalization scales to be discussed in connection with phenomenological applications of QCD factorization theorems. We observe that simultaneously preserving renormalization group invariance, Ward identities, and the basic sum rules in the definitions of parton densities forces these scales to be equal. The statement applies to generalized pole subtraction schemes that use dimensional regularization and to collinear factorization theorems for basic processes like deep inelastic scattering. We discuss implications for estimating the effects of scale sensitivity in phenomenological calculations, consistent extractions of Standard Model parameters alongside parton densities in global QCD analyses, and generally connecting phenomenologically extracted parton densities to first principles non-perturbative techniques like lattice QCD.
Comments:
20 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2608.01489 [pdf]
0 citations
23
[Submitted on 3 Aug 2026] (cross-list from hep-ph)
The $(2 + 1)$ -dimensional Gross-Neveu-Yukawa model at finite temperature, density, and magnetic field within the Functional Renormalization Group
Justin L.P. Mauldin🇩🇪 · Dirk H. Rischke🇩🇪
We investigate the phase diagram of the (2+1)-dimensional Gross-Neveu-Yukawa (GNY) model at finite temperature, density, and magnetic field beyond mean-field, using the Functional Renormalization Group (FRG) in the local potential approximation. Large magnetic fields result in magnetic catalysis, a dimensional reduction of the system, and enhancement of chiral symmetry breaking. We employ a hydrodynamical algorithm to solve the FRG flow equation for the effective potential, which allows for go further into the infrared region than with previously used methods. We find that the chiral condensate exhibits non-trivial behavior in various regions of the phase diagram: several first-order phase transitions and de Haas -- van Alphen oscillations at small magnetic field and large chemical potential, as well as a critical endpoint which shifts to higher temperature with increasing magnetic field.
Comments:
9 pages, 3 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2608.02280 [pdf]
1 citation

Affiliations

first authorsco-authorsvia INSPIRE