Quantum chromodynamics (QCD) is a fundamental theory describing quark interactions. Thus far, various quark models based on QCD have been widely used to study the properties of hadrons, including their structures and mass spectra. However, unlike quantum electrodynamics and Bohr's model of the hydrogen atom, a direct classical analogy is lacking for hadronic structures. This paper presents a classical interpretation of the nonrelativistic quark potential model, providing a more intuitive and visualizable description of strong interactions through the quantitative formulation of color charge and color flux. In addition, we establish the relationship between meson mass and its structural radius in the nonrelativistic framework and estimate key parameters of our model using available data from $ \eta_b(1S) $ and $ \Upsilon(1S) $ . Subsequently, we extend this relationship to a broader range of excited meson states and obtain their structural radii, which show good agreement with the root mean square radius or charge radius predicted by QCD calculations.

China

Zhiguang Tan

Youneng Guo

Shengjie Wang

Hua Zheng

Classical interpretation of nonrelativistic quark potential model: Color charge definition and meson mass-radius relationship * Supported in part by the Department of Education (21A0541) and Natural Science Foundation (2025JJ50382) of Hunan province, China

Spain

Arnau Bas i Beneito

John Gargalionis

Juan Herrero-García

Arcadi Santamaria

Australia

Michael Schmidt

Erratum: An EFT approach to baryon number violation: lower limits on the new physics scale and correlations between nucleon decay modes

The search for physics beyond the Standard Model (BSM) at collider experiments requires model-independent strategies to avoid missing possible discoveries of unexpected signals. Anomaly detection (AD) techniques offer a promising approach by identifying deviations from the Standard Model (SM) and have been extensively studied. The sensitivity of these methods to untunable hyperparameters has not been systematically compared, however. This study addresses it by investigating four semisupervised AD methods—AutoEncoders, Deep Support Vector Data Description, Histogram-based Outlier Score, and Isolation Forest—trained on simulated SM background events. In this paper, we study the sensitivity of these methods to BSM benchmark signals as a function of these untunable hyperparameters. Such a study is complemented by a proposal of a nonparametric permutation test using signal-agnostic statistics, which can provide a robust statistical assessment.

Portugal

Fernando Abreu de Souza

Maura Barros

Nuno F. Castro

United Kingdom

Miguel Crispim Romão

Céu Neiva

Rute Pedro

Sensitivity to new physics phenomena in anomaly detection: A study of untunable hyperparameters

We investigate the Berry phase arising from axion-photon and axion-fermion interactions. The effective Hamiltonians in both systems share the same form, enabling a unified description of the Berry phase and providing a novel perspective on axion experiments. We conceptually propose a new photon-ring experiment for axion detection. Furthermore, we demonstrate that measuring the axion-induced Berry phase offers a unique method for probing the global structure of the Standard Model gauge group and axion-related generalized symmetries.

Qing-Hong Cao

South Korea

Shuailiang Ge

Yandong Liu

Jun-Chen Wang

Berry phase in axion physics, SM global structure, and generalized symmetries

The 2HDM+S is the singlet extension of the two-Higgs-doublet model (2HDM). The singlet field and its mixing with the 2HDM Higgs sector lead to new contributions to the electroweak precision observables, in particular, the oblique parameters. In this study, we performed a systematic investigation of the impacts of each mixing angle on the oblique parameters. We adopted the mixing angles and physical Higgs masses as our parameters, which allow a mapping when a specific symmetry structure of the Higgs potential and various theoretical considerations are taken into account. We identified five benchmark cases, where at most one mixing angle was nonzero, and analyzed the 95% C.L. allowed parameter space using the oblique parameters. In the alignment limit of the 2HDM, we find that, other than the usual mass relations of $m_H\sim m_{H^\pm}$ or $m_A\sim m_{H^\pm}$ , electroweak precision measurements also impose an upper limit on the neutral Higgs masses. In the cases with nonzero singlet mixing with the 2HDM Higgses $\textit{H}$ or $\textit{A}$, we find approximate mass relations of $c^2_{\alpha_{HS}} m_{H} + s^2_{\alpha_{HS}}m_{h_S} = m_{H^\pm}$ or $c^2_{\alpha_{AS}} m_{A} + s^2_{\alpha_{AS}}m_{A_S} = m_{H^\pm}$ . These relations are universal to the 2HDM+S models, with or without further symmetry assumption. We also studied the non-alignment limit of the 2HDM+S, which typically has tighter constraints on the masses and mixing angles. Finally, we examined the complementarity between the electroweak precision analyses and the Higgs coupling precision measurements.

Cheng Li

Juxiang Li

Shufang Su

Wei Su

Electroweak precision constraints of the 2HDM+S * Cheng Li, Juxiang Li, and Wei Su are supported by the Natural Science Foundation of China (NSFC) (12305115), Shenzhen Science and Technology Program (202206193000001, 20220816094256002), Guangdong Provincial Key Laboratory of Gamma-Gamma Collider and Its Comprehensive Applications (2024KSYS001), and Guangdong Provincial Key Laboratory of Advanced Particle Detection Technology (2024B1212010005). Juxiang Li is also supported by the Fundamental Research Funds for the Central Universities, and the Sun Yat-sen University Science Foundation. Shufang Su is supported by the Department of Energy (DEFG02-13ER41976/DE-SC0009913)

In 2022, the collider detector at Fermilab (CDF) collaboration reported the $\textit{W}$-boson mass ( $ M_W= $ $ 80.4335\pm0.0094\; \text{GeV} $ ), which deviates from the standard model (SM) prediction ( $ M_W^{\rm SM}=80.357\pm0.006\; \text{GeV} $ ) by ~ $ 7\sigma $ . In contrast, the CMS collaboration obtained $ M_W=80.3602\pm0.0099\; \text{GeV} $ , which was very close to the SM global electroweak fit value of $ \sim80.357\; \text{GeV} $ . Motivated by this situation, we reassess the $\textit{W}$-boson mass within the lepton-specific two Higgs doublet model (LS-2HDM). To this end, we perform random scans (generated with SARAH 4.13.0 and evaluated with SPheno 4.0.3) and confront the results with up-to-date theoretical and experimental constraints. The scan enforces vacuum stability, perturbative unitarity, and perturbativity; electroweak precision observables via the oblique parameters $ (S,T,U) $ ; LEP bounds on $ H^\pm $ ; rare $\textit{B}$-meson decays; lepton flavor universality (LFU) in $\textit{Z}$ and $\textit{τ}$ decays; and 13 TeV LHC searches for additional Higgs bosons. Viable points are further tested with HiggsTools (HiggsSignals + HiggsBounds). In the LS-2HDM, if $ h_1 $ is the SM-like Higgs at $ m_{h_1}\simeq125 $ GeV with $ |\cos(\beta-\alpha)|\lesssim0.06 $ , $ 17\lesssim\tan\beta\lesssim39 $ , $ 144\lesssim m_{h_2}\lesssim414 $ GeV, and $ 435\lesssim m_{A,H^{\pm}}\lesssim685 $ GeV, the model reproduces the 2024 CMS $\textit{W}$-boson mass within $ 3\sigma $ . Solutions near the 2022 CDF value ( $ M_W=80.4335\pm0.0094\; \text{GeV} $ ) survive; however, after applying all constraints, including HiggsTools, they approach it at best within $ \lesssim2\sigma $ . Our findings emphasize that LS-2HDM favors the CMS results consistently with the current experimental results. Although one can theoretically accommodate the CDF results in this model, up-to-date electroweak precision bounds on oblique parameters $ (S,T,U) $ with the SM-like Higgs and LFU constraints exclude these solutions. Our results for $ W $ -boson mass can only be as close as about $ 2\sigma $ to $_{the CDF results}$.

Ali Çiçi

Hüseyin Dağ

Resolving the $\textit{W}$ boson mass in the lepton specific two Higgs doublet model * This work was supported in part by the Turkish Energy, Nuclear and Mineral Research Agency under project number 2022TENMAK(CERN)A5.H3.F2-02

The pion light-cone distribution amplitude (LCDA) is an essential nonperturbative input for a range of high-energy exclusive processes in quantum chromodynamics. Building on our previous work, the continuum limit of the fourth Mellin moment of the pion LCDA is determined in quenched QCD using quark masses which correspond to a pion mass of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>π</mi></msub><mo>=</mo><mn>550</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>. This calculation finds <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">⟨</mo><msup><mrow><mi>ξ</mi></mrow><mrow><mn>2</mn></mrow></msup><mo stretchy="false">⟩</mo><mo>=</mo><mn>0.202</mn><mo stretchy="false">(</mo><mn>8</mn><mo stretchy="false">)</mo><mo stretchy="false">(</mo><mn>9</mn><mo stretchy="false">)</mo></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">⟨</mo><msup><mrow><mi>ξ</mi></mrow><mrow><mn>4</mn></mrow></msup><mo stretchy="false">⟩</mo><mo>=</mo><mn>0.039</mn><mo stretchy="false">(</mo><mn>28</mn><mo stretchy="false">)</mo><mo stretchy="false">(</mo><mn>11</mn><mo stretchy="false">)</mo></mrow></math> where the first error indicates the combined statistical and systematic uncertainty from the analysis and the second indicates the uncertainty from working with Wilson coefficients computed to next-to-leading order. These results are presented in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mrow><mi>MS</mi></mrow><mo stretchy="true">¯</mo></mover></math> scheme at a renormalization scale of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>μ</mi><mo>=</mo><mn>2</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math>.

United States

William Detmold

Anthony V. Grebe

Japan

Issaku Kanamori

Taiwan

C.J. David Lin

Robert J. Perry

Yong Zhao

Parton physics from a heavy-quark operator product expansion: Lattice QCD calculation of the fourth moment of the pion distribution amplitude

Most existing and proposed high-energy neutrino experiments have excellent muon charge identification capabilities, enabling the distinction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>μ</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>μ</mi></msub></math> charged current interactions. In contrast, distinguishing electrons and positrons from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>e</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>e</mi></msub></math> interactions is typically impossible, as they quickly interact within the characteristically dense detector material and fail to reach the spectrometer. In this letter, we propose a compact and cost-effective plastic target, placed right before the spectrometer, to maximize the rate of electrons and positrons that reach the spectrometer before interacting. We demonstrate that, when installed at the FASER experiment, the Forward Physics Facility, or SHiP, this setup could enable the first separate measurement of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>e</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>e</mi></msub></math> cross sections at high energy. Additionally, this setup opens new opportunities to study forward particle production at collider neutrino experiments, such as constraining forward <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi></math> hyperon production, and, by reducing flux uncertainties, significantly improve limits on nonstandard neutrino interactions in neutral currents.

Germany

Felix Kling

Toni Mäkelä

Josh McFayden

Antielectron neutrinos at high-energy neutrino experiments: Identification strategies and physics potential

This investigation develops two exact anisotropic solutions determined by the Chaplygin equation of state within the context of Einstein’s gravity theory using the minimal geometric deformation. In order to accomplish this, we start with the anisotropic fluid acting as the seed source inside a static spherical interior. The gravitational interaction between the additional matter source and the seed (parent) fluid is then included in a Lagrangian that describes a new source. We compute the field equations for the full matter configuration and then transform the radial component to produce two independent systems of equations. Each set is imposed by different constraints that allow them to solve separately and leading to novel solutions. By matching the interior and exterior geometries using the suitable junction conditions, the constants that appear in the interior solutions are determined. The observed mass and radius of the compact star candidates $$Vela~X-1$$ and $$Cen~X-3$$ are then used to graphically examine the resulting models. We show that our solutions fulfill all the physical feasibility requirements for the chosen parameter values, indicating the workability of the gravitational decoupling approach in the current scenario.

Pakistan

Azerbaijan

Tayyab Naseer

M. Sharif

Aleena Tehreem

Saudi Arabia

Hamdy Thabet

Abdel-Haleem Abdel-Aty

Theoretical models of radially deformed relativistic stellar structures within the context of a realistic equation of state

We present the analysis techniques developed to explore the keV-scale energy region of the Cryogenic Underground Observatory for Rare Events (CUORE) experiment, based on more than 2 metric ton yr of data collected over five years. By prioritizing a stricter selection over a larger exposure, we are able to optimize data selection for thresholds at 10 keV and 3 keV with 691 kg yr and 11 kg yr of data, respectively. We study how the performance varies among the 988-detector array with different detector characteristics and data-taking conditions. We achieve an average baseline resolution of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.54</mn><mo>±</mo><mn>0.14</mn><mtext> </mtext><mtext> </mtext><mi>keV</mi></math> FWHM and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1.18</mn><mo>±</mo><mn>0.02</mn><mtext> </mtext><mtext> </mtext><mi>keV</mi></math> FWHM for the data selection at 10 keV and 3 keV, respectively. The analysis methods employed reduce the overall background by about an order of magnitude, reaching <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2.06</mn><mo>±</mo><mn>0.05</mn><mtext> </mtext><mtext> </mtext><mi>counts</mi><mo>/</mo><mo stretchy="false">(</mo><mi>keV</mi><mtext> </mtext><mi>kg</mi><mtext> </mtext><mi>days</mi><mo stretchy="false">)</mo></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>16</mn><mo>±</mo><mn>2</mn><mtext> </mtext><mtext> </mtext><mi>counts</mi><mo>/</mo><mo stretchy="false">(</mo><mi>keV</mi><mtext> </mtext><mi>kg</mi><mtext> </mtext><mi>days</mi><mo stretchy="false">)</mo></mrow></math> at the thresholds of 10 keV and 3 keV. We evaluate for the first time the near-threshold reconstruction efficiencies of the CUORE experiment, and find these to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>50</mn><mo>±</mo><mn>2</mn><mo>%</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>26</mn><mo>±</mo><mn>4</mn><mo>%</mo></math> at 10 keV and 3 keV, respectively. This analysis provides crucial insights into rare decay studies, new physics searches, and keV-scale background modeling with CUORE. We demonstrate that ton-scale cryogenic calorimeters can operate across a wide energy range, from keV to MeV, establishing their scalability as versatile detectors for rare event and dark matter physics. These findings also inform the optimization of future large mass cryogenic calorimeters to enhance the sensitivity to low-energy phenomena.