In this study, we investigate a scenario based on the effects of the Loop Quantum Gravity (LQG) on the electromagnetic sector of the Standard Model of Fundamental Interactions and Particle Physics (SM). Starting from a post-Maxwellian version of electromagnetism that includes LQG effects, we derive and discuss the influence of LQG parameters on classical quantities such as the components of the stress-tensor. Furthermore, we inspect the propagation of electromagnetic waves and examine the optical properties of the QED vacuum in this scenario. Among these, we contemplate the combined effect of the LQG parameters and a homogeneous background magnetic field on the propagation of electromagnetic waves by considering issues such as group velocities and refractive indices of the QED vacuum, in detail. Finally, with the aid of the previously analyzed LQG-extended photonic dispersion relations, we re-discuss the kinematics of the Compton effect and conclude that an interesting nonlinear profile emerges in the wavelengths of the incoming and deflected photons.

Brazil

P.A.L. Mourão

G.L.L.W. Levy

J.A. Helayël-Neto

Reassessing aspects of LQG-modified dispersion relations of photons * P. A. L. Mourão is support by CAPES. G. L. L. W. L. Levy is support by the Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Grant No. E-26/202.437/2024.

Several possible excesses around $ 95 $ GeV hint at an additional light scalar beyond the Standard Model. We examine the capability of the Circular Electron-Positron Collider (CEPC) to test this hypothesis in the Higgs-strahlung channel $ e^{+}e^{-} \to ZS $ with $ Z \to\mu^{+}\mu^{-} $ and $ S \to\tau^{+}\tau^{-} $ . A full detector simulation shows that the optimal center-of-mass energy for studying the 95 GeV light scalar is 210 GeV. A deep neural network classifier reduces the luminosity required for discovery by half. At $ L = 20\; \mathrm{ab}^{-1} $ , the $ 5\sigma $ sensitivity of the CEPC to the signal strength $ \mu_{\tau\tau}^{ZS} $ reaches 0.016 and 0.020 for $ \sqrt{s} = 210 $ GeV and 240 GeV, respectively. The corresponding thresholds for a 5% precision measurement are $ \mu_{\tau\tau}^{ZS} \gt 0.10 $ and $ \gt 0.12 $ . At $ \sqrt{s}=210 $ GeV (240 GeV), the $ 5\sigma $ coverage of all N2HDM-Flipped samples with $ \chi^2_{h_{95}} \lt 7.82 $ requires $ L=800\ \mathrm{fb}^{-1} $ (1.22 $ \mathrm{ab}^{-1} $ ). These results establish a 210 GeV run, augmented by machine-learning selection, as the most efficient strategy to confirm or refute the 95 GeV excess at future lepton colliders.

China

Yabo Dong

Manqi Ruan

Kun Wang

Haijun Yang

Jingya Zhu

Testing a 95 GeV Scalar at the CEPC with Machine Learning * This work was supported by the National Natural Science Foundation of China under Grant No. 12275066 and by the startup research funds of Henan University. The work of K. Wang was also supported by the Open Project of the Shanghai Key Laboratory of Particle Physics and Cosmology under Grant No. 22DZ2229013-3. The work of M. Ruan was also supported by the National Key Program for S&T Research and Development under Contract No. 2024YFA1610603. The work of H. Yang was also supported by the National Natural Science Foundation of China under Grant No. W2441004.

A model for the nuclear medium modification of parton densities is presented. The approach is based on a global analysis of available deep inelastic scattering data for different nuclear targets within the rescaling model, combined with the effects of Fermi motion. The scale dependence is implemented through the DGLAP-evolved quark and gluon densities in a proton derived analytically at the leading order of QCD coupling. By fitting the rescaling parameters to experimental data on the ratio $F_2^A(x,Q^2)/F_2^{A^\prime}(x,Q^2) $ for several nuclear targets $\textit{A}$ and $\textit{A}$', we obtain predictions for nuclear parton distributions, even for unmeasured nuclei. The effects of nuclear modifications are investigated with respect to the mass number $\textit{A}$. We highlight distinct shadowing and antishadowing behaviors for gluons and quarks.

Russia

A.V. Kotikov

A.V. Lipatov

A simple model for nuclear modification of parton distribution functions * This research has been carried out at the expense of the Russian Science Foundation grant 25-22-00066, https://rscf.ru/en/project/25-22-00066/

We construct a formalism that describes the resonances decaying into four pseudoscalar meson final states. This method is fully covariant and can be directly applied to the partial-wave analysis of high statistical data. Two topologies of the process are considered: two intermediate resonances, each decaying into two final mesons, and cascade decay via three meson intermediate states. In particular, we consider the production of such states in the central collision reactions and in radiative $J/\Psi$ decay.

M.A. Matveev

A.T. Sitnikov

A.V. Sarantsev

Tensor formalism for the partial wave analysis of reactions with resonances decaying into four pseudoscalar mesons * Supported by the RSF (Grant No. 24-22-00322)

High-precision regression of physical parameters from black hole images generated by General Relativistic Ray Tracing (GRRT) is essential for investigating spacetime curvature and advancing black hole astrophysics. However, owing to limitations in observational resolution, high observational costs, and imbalanced distributions of positive and negative samples, black hole images often suffer from data scarcity, sparse parameter spaces, and complex structural characteristics. These factors pose significant challenges to conventional regression methods based on simplified physical models. To overcome these challenges, this study introduces the Multiscale Adaptive Network (MANet), a novel regression framework grounded in deep learning. MANet integrates an Adaptive Channel Attention (ACA) module to selectively enhance features in physically informative regions. Meanwhile, a Multiscale Enhancement Feature Pyramid (MEFP) is employed to capture fine-grained spatial structures, such as photon rings and accretion disks, while alleviating information loss due to downsampling. Experimental evaluations on GRRT-simulated datasets demonstrate that MANet substantially improves parameter estimation accuracy and generalization capability in high-dimensional parameter spaces, outperforming existing baseline approaches. This framework presents a promising avenue for high-precision parameter regression in Event Horizon Telescope (EHT) data analysis and broader astrophysical imaging applications characterized by sparse and noisy data.

Jialei Wei

Ao Liu

Dejiang Li

Cuihong Wen

Physical parameter regression from black hole images using a multiscale adaptive neural network * Supported by the Natural Science Foundation of Hunan Province under grant No. 2023JJ30384; the National Natural Science Foundation of China under Grants No. 12374408; the University Students' Innovation and Entrepreneurship Training Program Project

We use a modified relativistic quark model to study the properties of excited charmed and charmed strange mesons. We calculate the masses and wave functions of conventional charmed and charmed strange mesons incorporating both spin and $\textit{S}$-$\textit{D}$ mixing effects and fit parameters of the potential model with known experimental states using differential evolution techniques. Using leading Born-Oppenheimer expansion, we compute the spectrum and wave functions of the first gluonic excited state of charmed and charmed strange mesons. We examine the effects of gluonic excitation on the spectrum of the resulting hybrid mesons. Using our calculated spectrum and wave functions, we determine the radiative transitions of the conventional and hybrid open charm mesons. We compare our calculations with experimental data and other works. We expect our results will be beneficial in the detection of charmed and charmed strange conventional and hybrid mesons.

Pakistan

Saba Noor

Faisal Akram

Bilal Masud

Study of excited $\textit{D}$ and D$_{s}$ mesons in a relativized quark model * F. A. acknowledges HEC grant 20-15728/NRPU/R&D/HEC/2021, Pakistan

We investigate the properties of the radially excited charged pion, with a specific focus on its electromagnetic form factor (EFF) and its box contribution to the hadronic light-by-light (HLbL) component of the muon's anomalous magnetic moment, $ a_{\mu} $ . Utilizing a coupled non-perturbative framework combining Schwinger-Dyson and Bethe-Salpeter equations, we first compute the mass and weak decay constant of the pion's first radial excitation. Initial results are provided for the Rainbow-Ladder (RL) approximation, followed by an extended beyond RL (BRL) analysis that incorporates meson cloud effects. Building on our previous work, this analysis demonstrates that an accurate description of the first radial excitation can be achieved without the need for a reparametrization of the interaction kernels. Having demonstrated the effectiveness of the truncation scheme, we proceed to calculate the corresponding EFF, from which we derive the contribution of the pion's first radial excitation to the HLbL component of the muon's anomalous magnetic moment, producing $ a_{\mu}^{\pi_1-\text{box}}(\text{RL}) = -(2.03 \pm 0.12) \times 10 ^{-13} $ , $ a_{\mu}^{\pi_1-\text{box}}(\text{BRL}) = $ $ -(2.02 \pm 0.10) \times 10 ^{-13} $ . Our computation also sets the groundwork for calculating related pole contributions of excited pseudoscalar mesons to $ a_{\mu} $ .

Spain

Mexico

Angel S. Miramontes

K. Raya

A. Bashir

P. Roig

G. Paredes-Torres

Radially excited pion: electromagnetic form factor and the box contribution to the muon's $\textit{g}$-2 * A. S. Miramontes acknowledges $\textit{Consejo Nacional de Ciencia, Humanidades y Tecnología}$ (CONAHCyT), Mexico, for the financial support received through the program '$\textit{Postdoctorados Nacionales por México}$', additionally, has been partially funded by the 'PROMETEO' programme of the 'Generalitat Valenciana' grant CIPROM/2022/66, and by the Spanish 'Agencia Estatal de Investigación', MCIN/AEI/10.13039/501100011033, through the grants PID2020-113334GB-I00 and PID2023-151418NB-I00. A. Bashir thanks $\textit{Coordinación de la Investigación Científica}$ of the $\textit{Universidad Michoacana de San Nicolás de Hidalgo}$ Grant No. 4.10., CONAHCyT grant CBF2023-2024-3544 and $\textit{Ayudas Beatriz Galindo}$, Spain. P. Roig acknowledges Conahcyt (México) funding through project CBF2023-2024-3226 as well as Spanish support during his sabbatical year through projects MCIN/AEI/10.13039/501100011033, grant PID2020-114473GB-I00, and Generalitat Valenciana grant PROMETEO/2021/071. G. Paredes-Torres acknowledges CONAHCyT, Mexico, for the financial support provided to him through the program '$\textit{Beca de Posgrado en México}$'. The work of A. Bashir and K. Raya is supported by Spanish Ministry of Science and Innovation (MICINN grant no. PID2022-140440NB-C22) and Junta de Andalucía (grant P18-FR-5057)

With the discovery of a Higgs boson with a mass of 125 gigaelectronvolts (GeV) at the Large Hadron Collider (LHC) at CERN in 2012, the Standard Model (SM) is complete, and despite intensive searches, no new fundamental particle has been observed since then. In fact, a discovery can be challenging without a predictive new physics model because different channels and observables cannot be combined directly and unambiguously. Furthermore, without supporting indirect hints, the signal space to be searched is huge, resulting in diluted significances owing to the look-elsewhere effect. Several LHC processes with multiple leptons in the final state point towards the existence of a new Higgs boson with a mass between 140 GeV to 160 GeV decaying mostly to $\textit{W}$ bosons. While the former strongly reduces the look-elsewhere effect, the latter indicates that it could be a Higgs triplet with zero hypercharge. Within this simple and predictive extension of the SM, we simulate and combine different channels of di-photon production in association with leptons, missing energy, jets, $\textit{etc}$... Using the full run-2 results by ATLAS, including those presented recently at the Moriond conference, an increased significance of 4 standard deviations is obtained for a $\approx$ 152 GeV Higgs. Due to the previously predicted mass range, the look-elsewhere effect is negligible, and this constitutes the highest statistical evidence for a new narrow resonance obtained at the LHC. Furthermore, the model predicts a heavier-than-expected $\textit{W}$ boson, as indicated by the global electroweak fit. If further substantiated, the discovery of a new Higgs would overthrow the SM, provide a compelling case for the construction of future particle colliders, and pave the way to a novel understanding of the known shortcomings of the SM. In particular, the triplet Higgs field can lead to a strong first-order phase transition and could thus be related to the matter anti-matter asymmetry in our Universe.

Switzerland

Andreas Crivellin

Saiyad Ashanujjaman

Sumit Banik

Guglielmo Coloretti

India

Siddharth P. Maharathy

South Africa

Bruce Mellado

Growing evidence for a Higgs triplet * The work of Andreas Crivellin is supported by a Professorship Grant from the Swiss National Science Foundation (PP00P21_76884). The work of Saiyad Ashanujjaman is partially supported by the National Natural Science Foundation of China (11835013). Siddharth P. Maharathy acknowledges using the SAMKHYA: High-Performance Computing Facility provided by the Institute of Physics, Bhubaneswar

Studying percolation phase transitions offers valuable insights into the characteristics of phase transitions, shedding light on the underlying mechanisms that govern the formation of global connectivity within a system. We explore the percolation phase transition in the 3D cubic Ising model by employing two machine learning techniques. Our results demonstrate that machine learning methods can distinguish different phases during the percolation transition. Through the finite-size scaling analysis on the output of the neural networks, the percolation temperature and a correlation length exponent in the geometrical percolation transition are extracted and compared to those in the thermal magnetization phase transition within the 3D Ising model. These findings provide a valuable method for enhancing our understanding of the properties of the QCD critical point, which belongs to the same universality class as the 3D Ising model.

Ranran Guo

Xiaobing Li

Rui Wang

United Kingdom

Shiyang Chen

Yuanfang Wu

Zhiming Li

Exploring percolation phase transition in the three-dimensional Ising model with machine learning * Supported by the National Key Research and Development Program of China (2024YFE0110103, 2022YFA1604900), the National Natural Science Foundation of China (12275102), and the Chinese Scholarship Council Grant (202306770049)

Using an electron-positron collision data sample corresponding to $ (1.0087\pm0.0044)\times10^{10} $ $ J/\psi $ events collected using the BESIII detector at the BEPCII collider, we firstly search for the lepton number violation decay $ \phi \to \pi^+ \pi^+ e^- e^- $ via $ J/\psi\to \phi\eta $ . No obviously signals are found. The upper limit on the branching fraction of $ \phi \to \pi^+ \pi^+ e^- e^- $ is set to be $ 1.3\times10^{-5} $ at the 90% confidence level.

M. Ablikim

M.N. Achasov

Sweden

P. Adlarson

Germany

O. Afedulidis

X.C. Ai

R. Aliberti

Italy

A. Amoroso

M.R. An

Q. An

Y. Bai

O. Bakina

I. Balossino

Y. Ban

H.R. Bao

Poland

V. Batozskaya

Mongolia

K. Begzsuren

N. Berger

M. Berlowski

M. Bertani

D. Bettoni

F. Bianchi

E. Bianco

A. Bortone

I. Boyko

United States

R.A. Briere

A. Brueggemann

H. Cai

X. Cai

A. Calcaterra

G.F. Cao

N. Cao

Türkiye

S.A. Cetin

J.F. Chang

G.R. Che

Y.Z. Che

G. Chelkov

C. Chen

Chao Chen

G. Chen

H.S. Chen

M.L. Chen

S.J. Chen

S.L. Chen

S.M. Chen

T. Chen

X.R. Chen

X.T. Chen

Y.B. Chen

Y.Q. Chen

Z.J. Chen

Z.Y. Chen

S.K. Choi

G. Cibinetto

S.C. Coen

F. Cossio

J.J. Cui

H.L. Dai

J.P. Dai

A. Dbeyssi

R.E. de Boer

D. Dedovich

Z.Y. Deng

A. Denig

I. Denysenko

M. Destefanis

F. De Mori

B. Ding

X.X. Ding

Y. Ding

J. Dong

L.Y. Dong

M.Y. Dong

X. Dong

M.C. Du

S.X. Du

Z.H. Duan

P. Egorov

Y.H. Fan

J. Fang

S.S. Fang

W.X. Fang

Y. Fang

Y.Q. Fang

R. Farinelli

L. Fava

F. Feldbauer

G. Felici

C.Q. Feng

J.H. Feng

K. Fischer

M. Fritsch

C.D. Fu

J.L. Fu

Y.W. Fu

H. Gao

Y.N. Gao

Yang Gao

S. Garbolino

I. Garzia

Search for the lepton number violation decay $\textit{ϕ}$ → $\textit{π}$ $^{+}$ $\textit{π}$ $^{+}$ $\textit{e}$ $^{−}$ $\textit{e}$ $^{−}$ via $\textit{J}$/$\textit{ψ}$ → $\textit{ϕη}$ * The BESIII Collaboration appreciates the staff of BEPCII and the IHEP Computing Center for their strong support. This work is supported in part by the National Key R&D Program of China (2020YFA0406300, 2020YFA0406400); National Natural Science Foundation of China (NSFC) (12035009, 11635010, 11735014, 11835012, 11935015, 11935016, 11935018, 11961141012, 12025502, 12035013, 12061131003, 12192260, 12192261, 12192262, 12192263, 12192264, 12192265, 12221005, 12225509, 12235017); the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; the CAS Center for Excellence in Particle Physics (CCEPP); Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (U1832207); CAS Key Research Program of Frontier Sciences (QYZDJ-SSW-SLH003, QYZDJ-SSW-SLH040); 100 Talents Program of CAS; the Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology; the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement (894790); the German Research Foundation DFG (455635585), the Collaborative Research Center CRC 1044, FOR5327, GRK 2149; Istituto Nazionale di Fisica Nucleare, Italy; Knut and Alice Wallenberg Foundation (2021.0174, 2021.0299); Ministry of Development of Turkey (DPT2006K-120470); National Research Foundation of Korea (NRF-2022R1A2C1092335); National Science and Technology Fund of Mongolia; National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation of Thailand (B16F640076); Polish National Science Centre (2019/35/O/ST2/02907); Swedish Research Council (2019.04595); the Swedish Foundation for International Cooperation in Research and Higher Education (CH2018-7756); and the U. S. Department of Energy (DE-FG02-05ER41374).