Moscow University Physics Bulletin最新文献

{"title":"Spectroscopy of Doubly Charmed Tetraquarks in the Relativistic Quark Model","authors":"V. O. Galkin,&nbsp;E. M. Savchenko","doi":"10.3103/S0027134925702467","DOIUrl":"10.3103/S0027134925702467","url":null,"abstract":"<p>Motivated by the recent experimental observations of the exotic narrow doubly charmed tetraquark <span>(T_{cc}(3875)^{+})</span>, the spectroscopy of such tetraquarks is investigated within the relativistic quark model, based on the quasipotential approach and QCD. Tetraquark is considered as a diquark–antidiquark bound state. Relativistic quasipotential includes all relativistic corrections and accounts for the finite size of a diquark. Masses of doubly charmed tetraquarks are calculated and then compared with available experimental data and the strong fall-apart decay thresholds into a pair of mesons. The states that could be observed as narrow resonances in other decay modes are identified.</p>","PeriodicalId":711,"journal":{"name":"Moscow University Physics Bulletin","volume":"80 :\nHigh","pages":"S677 - S684"},"PeriodicalIF":0.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Transverse Momentum Dependent Gluon Distribution in Proton and Nuclei","authors":"M. A. Malyshev,&nbsp;A. V. Lipatov,&nbsp;G. I. Lykasov","doi":"10.3103/S0027134925702388","DOIUrl":"10.3103/S0027134925702388","url":null,"abstract":"<p>We present a new transverse momentum dependent (unintegrated) gluon distribution function in proton. Parameters of this distribution at low <span>(Q^{2})</span> were obtained from a fit on soft hadron production data taken at LHC and <span>(F_{2}(x,Q^{2}))</span> and reduced cross section data from HERA. Some parameters were determined from a fit on HERA and LHC data at larger <span>(Q^{2})</span>, such as heavy flavor jet, Higgs boson and prompt photon production. Then we extend our consideration to nuclei using the property of geometrical scaling. We show that one can describe the shadowing effect at low <span>(x)</span> using our nuclear gluon density within the color dipole approach.</p>","PeriodicalId":711,"journal":{"name":"Moscow University Physics Bulletin","volume":"80 :\nHigh","pages":"S603 - S613"},"PeriodicalIF":0.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Foundation Models of Ocean and Atmosphere in 2025: Milestones and Perspectives","authors":"M. A. Krinitskiy","doi":"10.3103/S0027134925703084","DOIUrl":"10.3103/S0027134925703084","url":null,"abstract":"<p>Foundation models–large neural networks pretrained on heterogeneous Earth-system datasets and adapted to multiple tasks–are reshaping atmospheric and oceanic prediction. In this overview, we contrast this paradigm with task-specific supervised learning, review major atmospheric models (FourCastNet, ClimaX, Pangu-Weather, GraphCast, FengWu, FuXi, Prithvi WxC, AIFS, Aurora) and the first wave of oceanic models (WenHai, XiHe, LangYa), outline applications (forecasting, downscaling, statistical correction, subseasonal/seasonal prediction, analogs discovery, climate risk), and discuss challenges and perspectives including upcoming Russian initiatives.</p>","PeriodicalId":711,"journal":{"name":"Moscow University Physics Bulletin","volume":"80 :","pages":"S1244 - S1261"},"PeriodicalIF":0.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the TAIGA-HiSCORE Data Using the Latent Space of Autoencoders","authors":"Yu. Yu. Dubenskaya,&nbsp;S. P. Polyakov,&nbsp;A. P. Kryukov,&nbsp;A. P. Demichev,&nbsp;E. O. Gres,&nbsp;E. B. Postnikov,&nbsp;A. Yu. Razumov,&nbsp;P. A. Volchugov,&nbsp;D. P. Zhurov","doi":"10.3103/S0027134925702923","DOIUrl":"10.3103/S0027134925702923","url":null,"abstract":"<p>The aim of extensive air shower (EAS) analysis is to reconstruct the physical parameters of the primary particle that initiated the shower. The TAIGA experiment is a hybrid detector system that combines several imaging atmospheric Cherenkov telescopes (IACTs) and an array of nonimaging Cherenkov detectors (TAIGA-HiSCORE) for EAS detection. Because the signals recorded by different detector types differ in physical nature, the direct merging of data is unfeasible, which complicates multimodal analysis. Currently, to analyze data from the IACTs and TAIGA-HiSCORE, a set of auxiliary parameters specific to each detector type is calculated from the recorded signals. These parameters are chosen empirically, so there is no certainty that they retain all important information contained in the experimental data and are the best suited for the respective problems. We propose to use autoencoders (AE) for the analysis of TAIGA experimental data and replace the conventionally used auxiliary parameters with the parameters of the AE latent space. The advantage of the AE latent space parameters is that they are not biased by pre-established assumptions and constraints and still contain in a compressed form the physical information obtained directly from the experimental data. This approach also holds potential for enabling seamless integration of heterogeneous IACT and HiSCORE data through a joint latent space. To reconstruct the parameters of the primary particle of the EAS from the latent space of the AE, a separate artificial neural network is used. In this paper, the proposed approach is used to reconstruct the energy of the EAS primary particles based on Monte Carlo simulation data for TAIGA-HiSCORE. The dependence of the energy determination accuracy on the dimensionality of the latent space is analyzed, and these results are also compared with the results obtained by the conventional technique. For signals recorded by TAIGA-HiSCORE, it is shown that when using the AE latent space, the energy of the primary particle is reconstructed with satisfactory accuracy.</p>","PeriodicalId":711,"journal":{"name":"Moscow University Physics Bulletin","volume":"80 :","pages":"S1033 - S1041"},"PeriodicalIF":0.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal Difference Modulated Spiking Actor Learning","authors":"Y. Tihomirov,&nbsp;R. Rybka,&nbsp;A. Serenko,&nbsp;A. Sboev","doi":"10.3103/S0027134925702935","DOIUrl":"10.3103/S0027134925702935","url":null,"abstract":"<p>Although neuromorphic computing achieves significant energy savings through spiking neural networks (SNNs), developing efficient methods suitable for hardware deployment for reinforcement learning in SNNs remains a challenging task. We present a new two-layer spiking neural network architecture for the actor part of the actor-critic framework. The main contribution is in the actor hidden layer that learns state representations via unsupervised spike-timing dependent plasticity (STDP), which clusters input states. The output layer is trained with temporal-difference-modulated STDP (TD-STDP) using the critic’s TD error. The actor hidden layer’s outputs can be directly reused by a spiking critic as fixed features, which allows cutting the number of critic parameters and enabling a fully local three-factor plasticity pipeline. Evaluated on the classic Acrobot and CartPole control tasks, our SNN-based actor demonstrates performance comparable to recent SNN baselines. Creating reinforcement learning methods based on local plasticity learning rules is important for future implementation on neuromorphic hardware.</p>","PeriodicalId":711,"journal":{"name":"Moscow University Physics Bulletin","volume":"80 :","pages":"S1101 - S1108"},"PeriodicalIF":0.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gradient Boosting Ensemble Adaptation for Geophysical Inverse Problems under Data Scarcity","authors":"M. K. Shaleev,&nbsp;I. V. Isaev,&nbsp;I. E. Obornev,&nbsp;S. A. Dolenko","doi":"10.3103/S0027134925703047","DOIUrl":"10.3103/S0027134925703047","url":null,"abstract":"<p>This study investigates model adaptation strategies using gradient boosting (LightGBM) for solving inverse problems in exploration geophysics focused on reconstructing spatial distributions of subsurface properties from surface measurements. Addressing limitations of traditional approaches requiring exhaustive site-specific training, we implement four model adaptation strategies: incremental training, pruning and extending, source-target model ensemble, and feature space augmentation. Experiments employ three synthetic datasets of progressive geological complexity—homogeneous (Easy), pattern variable (Medium), and spatially heterogeneous (Hard), representing a Norilsk-type four-layer section with gravimetric, magnetic, and magnetotelluric measurements. Results demonstrate that gradient boosting achieves solution accuracy comparable to neural networks while reducing computational costs. At the same time, the use of gradient boosting adaptation allows one to further reduce computational costs. The study creates an effective basis for geophysical research in conditions of limited data.</p>","PeriodicalId":711,"journal":{"name":"Moscow University Physics Bulletin","volume":"80 :","pages":"S1148 - S1156"},"PeriodicalIF":0.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Full Electroweak (boldsymbol{mathcal{O}(alpha)}) Corrections to Higgs Boson Production Processes with the Beam Polarization at the International Linear Collider","authors":"Junpei Fujimoto,&nbsp;My Uyen Nhi Quach,&nbsp;Yoshimasa Kurihara","doi":"10.3103/S0027134925702315","DOIUrl":"10.3103/S0027134925702315","url":null,"abstract":"<p>We present the full <span>({mathcal{O}}(alpha))</span> electroweak radiative corrections to nine Higgs boson production processes with beam polarization at the International Linear Collider (ILC). The computations are performed with the help of GRACE-LOOP. We compared the full <span>({mathcal{O}}(alpha))</span> electroweak corrections with the factorized initial-state radiation(ISR) effects in order to estimate the pure weak corrections. We find that the pure weak corrections are nonnegligible and must be taken into account for the precision measurements of Higgs-boson properties at the ILC.</p>","PeriodicalId":711,"journal":{"name":"Moscow University Physics Bulletin","volume":"80 :\nHigh","pages":"S554 - S563"},"PeriodicalIF":0.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HQCD for Heavy Quarks: String Tension in Magnetic Field","authors":"K. A. Rannu,&nbsp;I. Ya. Aref’eva,&nbsp;P. S. Slepov","doi":"10.3103/S0027134925702686","DOIUrl":"10.3103/S0027134925702686","url":null,"abstract":"<p>Within a holographic framework, we analyze the impact of an external magnetic field on the string tension of timelike Wilson loops in a hot and dense QCD medium in the heavy quark limit.</p>","PeriodicalId":711,"journal":{"name":"Moscow University Physics Bulletin","volume":"80 :\nHigh","pages":"S841 - S847"},"PeriodicalIF":0.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discription of the Dinamics of Fermions by the Influence Functional Method","authors":"A. A. Biryukov,&nbsp;M. A. Shleenkov","doi":"10.3103/S0027134925702601","DOIUrl":"10.3103/S0027134925702601","url":null,"abstract":"<p>We consider a system of interacting spinor and electromagnetic fields. We describe the quantum state of the fields by a statistical density matrix. We present the equation of evolution of the density matrix of the field system in the method of integration over trajectories. The evolution equation for the density matrix of the fermion field is obtained as an averaging of the functional of the influence of the electromagnetic field. An explicit form of the functional of the influence of the electromagnetic field is found. We present the equations of motion for the fermion field taking into account the influence of the vacuum of the electromagnetic field.</p>","PeriodicalId":711,"journal":{"name":"Moscow University Physics Bulletin","volume":"80 :\nHigh","pages":"S781 - S787"},"PeriodicalIF":0.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On Lagrangian Formulations for (Ir)Reducible Mixed-Antisymmetric Higher Integer Spin Fields in Minkowski Spaces","authors":"Alexander A. Reshetnyak,&nbsp;Julia V. Bogdanova,&nbsp;Vipul K. Pandey","doi":"10.3103/S0027134925702480","DOIUrl":"10.3103/S0027134925702480","url":null,"abstract":"<p>We extend the results of Lagrangian formulations study to construct gauge-invariant Lagrangians for (ir)reducible integer higher-spin massless and massive representations of the Poincaré group with a Young tableau <span>(Y[hat{s}_{1},hat{s}_{2},hat{s}_{3}])</span> in <span>(d)</span>-dimensional flat space-time (as the probable candidates to describe the dark matter problem beyond the SM). These particles are described within a metric-like formulation by tensor fields with 3 groups of antisymmetric Lorentz indices <span>(Phi_{mu^{1}[{hat{s}_{1}}],mu^{2}[{hat{s}_{2}}],mu^{3}[{hat{s}_{3}}]})</span> on a basis of the BRST method with complete, <span>(Q)</span>, and incomplete, <span>(Q_{c})</span>, BRST operators. We found unconstrained (with <span>(Q)</span>) and constrained (with <span>(Q_{c})</span> and off-shell BRST invariant holonomic constraints) gauge Lagrangian formulations with different configuration spaces and reducibility stages. The deformation procedure to construct interacting gauge model with mixed-antisymmetric fields is proposed.</p>","PeriodicalId":711,"journal":{"name":"Moscow University Physics Bulletin","volume":"80 :\nHigh","pages":"S692 - S702"},"PeriodicalIF":0.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}