?
Search for long-lived particles decaying to e±μ∓ν
The European Physical Journal C - Particles and Fields. 2021. Vol. 81. No. 261. P. 1–16.
Aaij R., Beteta C. A., Boldyrev A., Derkach D., Hushchyn M., Karpov M., Kazeev N., Maevskiy A., Ratnikov F., Ryzhikov A., Ustyuzhanin A.
Long-lived particles decaying to e±μ∓νe±μ∓ν, with masses between 7 and 5050 GeV/c22 and lifetimes between 2 and 5050 ps, are searched for by looking at displaced vertices containing electrons and muons of opposite charges. The search is performed using 5.45.4 fb−1−1 of pppp collisions collected with the LHCb detector at a centre-of-mass energy of s√=13s=13 TeV. Three mechanisms of production of long-lived particles are considered: the direct pair production from quark interactions, the pair production from the decay of a Standard-Model-like Higgs boson with a mass of 125125 GeV/c22, and the charged current production from an on-shell WW boson with an additional lepton. No evidence of these long-lived states is obtained and upper limits on the production cross-section times branching fraction are set on the different production modes.
Keywords: Large Hadron ColliderExperimental High Energy Physics and Elementary Particles PhysicsФизика высоких энергийCERNБольшой адронный коллайдерЦЕРН
Publication based on the results of:
Bisnovatyi-Kogan G., Kondratyev I., Moiseenko S. G., International Journal of Modern Physics A 2025 Vol. 40 No. 7 Article 2550018
Bright transient objects in different wave bands have been discovered in recent years.
To explain these short (from ms to s), and very powerful events, different models, galactic and
extragalactic, have been considered. One of the popular models is based on the suggestion of
transformation of the magnetized plasma blob, presumably a magnetohydrodynamic (MHD)
shock wave, moving with relativistic ...
Added: May 11, 2026
Торопина О. Д., Бисноватый-Коган Г. С., Moiseenko S. G., Astronomy Reports 2025 Vol. 69 No. Suppl. 1 P. 80–90
The results of MHD simulations of supersonic astrophysical and laboratory jets in an external
poloidal magnetic field (Br,Bz) taking into account the rotation of the matter, are presented. The ejected
matter is collimated by the magnetic field, the degree of collimation and the flow structure depend on the
relation between of the magnetic field induction and the angular ...
Added: May 11, 2026
Morozov E. V., Demin A. S., Borovitskaya I. V. et al., Inorganic Materials: Applied Research 2026 Vol. 17 No. 3 P. 619–626
This article presents the results of experiments on the impact of powerful pulsed ion-plasma and
electron flows generated in the working chamber of the Plasma Focus PF-5M installation during each highvoltage
discharge on a model aluminum alloy B95. It is shown that the general characteristics of the alloy’s
damage upon exposure to pulsed flows of helium ions (HI) ...
Added: May 4, 2026
Derkacheva A., Sakirkina M., Kraev G. et al., /. 2026.
Comprehensive data on natural hazards and their consequences are crucial for effective for risk assessment, adaptation planning, and emergency response. However, many countries face challenges with fragmented, inconsistent, and inaccessible data, particularly regarding local-scale events. To address this data gap in Russia, we developed an end-to-end processing pipeline that scrapes news from various online sources, ...
Added: April 28, 2026
Ponomarev A., Aleksandrov N., Plasma Physics Reports 2026 Vol. 52 No. 3 P. 367–378
An approximate method for calculating drift velocity and other kinetic coefficients of heavy ions
in a light gas is generalized to gaseous mixtures. Obtained equations are used to calculate the mobilities of
and ions, as well as rate constants for inelastic ion–molecule processes with these ions in helium with
small additions of O2 under an electric field. Calculated ...
Added: April 27, 2026
Domrin V. I., Malova H. V., V. Yu. Popov et al., Cosmic Research 2026 Vol. 64 No. 2 P. 238–252
During magnetospheric perturbations a relatively thin current sheet with thickness about several
proton gyroradii forms in the Earth’s magnetotail. In a framework of the kinetic model describing current
sheet thinning in the magnetotail, the processes of its formation are investigated depending on the normal
magnetic field magnitude which affects both the current sheet structure and particle dynamics within ...
Added: April 27, 2026
Tsareva O. O., Malova H. V., V. Yu. Popov et al., Plasma Physics Reports 2026 Vol. 52 No. 2 P. 179–185
The influence of asymmetry of plasma sources on the structure and spatial localization of a superthin
current sheet (STCS) supported by demagnetized electrons is studied using a self-consistent model. The
simulation takes into account the presence of a single plasma source in the northern hemisphere, which
makes the plasma flow asymmetric. It is demonstrated that the asymmetry of ...
Added: April 27, 2026
П.А.Беспалов, О.Н. Савина, Геомагнетизм и аэрономия 2025 Т. 65 № 5 С. 620–628
Several basic models of frequency dynamics in quasi-periodic VLF emissions with spectral form repetition
periods from 10 to 300 s are considered. In all cases, we are talking about manifestations of cyclotron instability
of electron radiation belts thet are well described within the framework of the plasma magnetospheric maser
theory based an the averaged self-consistent system of quasi-linear ...
Added: April 25, 2026
Bondarenko G.G., Fisher M. R., Kristya V. I., Bulletin of the Russian Academy of Sciences: Physics 2026 Vol. 90 No. 4 P. 572–576
A model of the cathode layer of a glow gas discharge with a thin dielectric film on a fraction of the
cathode’s working surface is formulated. It is shown that a glow discharge most rapidly transits to an arc discharge,
accompanied by a significant increase in discharge current density and a decrease in cathode voltage
drop, if the ...
Added: April 25, 2026
Lu X., Tognazzi A., Klimov V. et al., Plasmonics 2026 Vol. 21 P. 1503–1512
Plasmonic nanostructures typically exhibit shifts in their resonant wavelength in response to changes in the refractive index of the surrounding medium. This limits their applications in scenarios requiring stable optical resonances. Here we present a metallic-dielectric hybrid metasurface that exhibits stable multi-wavelength resonance even if the refractive index of its surrounding varies. To quantitatively evaluate the stability of ...
Added: April 22, 2026
Shchur L., Antonov D., Burovski E., International Journal of Bifurcation and Chaos in Applied Sciences and Engineering 2026 P. 1–9
We present a simple model that simulates the possible influence of one society on another. Specifically, two societies evolve deterministically according to the well-known Nowak-May spatial game with the addition of mutual influence through connections that reflect the current states of the societies. This may be related to the influence of a global information resource ...
Added: April 20, 2026
Qin X., Deng Y., Shchur L. et al., / Series arXiv "math". 2026. No. 2603.02962.
We perform a Monte Carlo analysis of the Ising model on many three-dimensional lattices. By means of finite-size scaling we obtain the critical points and determine the scaling dimensions. As expected, the critical exponents agree with the three-dimensional Ising universality class for all models. The irrelevant field, as revealed by the correction-to-scaling amplitudes, appears to ...
Added: April 20, 2026
Pilé I., Deng Y., Shchur L., / Series arXiv "math". 2026. No. 2604.10254.
We investigate the spatial overlap of successive spin configurations in Markov chain Monte Carlo simulations using the local Metropolis algorithm and the Svendsen-Wang and Wolff cluster algorithms. We examine the dynamics of these algorithms for two models in different universality classes: the Ising model and the Potts model with three components. The overlap of two ...
Added: April 20, 2026
Doronin S. V., Budkov Y., Current Opinion in Electrochemistry 2026 Vol. 57 Article 101853
The electric double layer (EDL) governs charge distribution at electrode–electrolyte interfaces, controlling reaction kinetics and energy storage performance. This mini review surveys the evolution of EDL theory—from the classical Gouy-Chapman-Stern framework to modern coupled quantum-continuum schemes that integrate electronic structure with statistical mechanics. We show how modified Poisson–Boltzmann (mPB) formu-lations incorporating finite ion size, dielectric ...
Added: April 19, 2026
Nikolai N. Kalikin, Petr E. Brandyshev, Yury A. Budkov, Journal of Chemical Physics 2026 Vol. 164 No. 15 Article 154904
This study presents a mean-field theory for zwitterionic polymer solutions confined within attractive slit-like nanopores. Building upon our prior model for self-coacervation [Budkov et al., Soft Matter 19, 3281–3289 (2023)], we demonstrate that strong electrostatic dipole–dipole correlations between monomeric units, coupled with attraction to pore walls, can induce capillary-driven liquid–liquid phase separation inside the pore—a ...
Added: April 18, 2026
Moiseev E., D.A. Masyutin, I.A. Melnichenko et al., Optics and Laser Technology 2026 Vol. 201 No. 115289 Article 115289
Lasing at a wavelength near 255 nm is demonstrated in AlGaN whispering gallery mode microlasers with radii ranging from 1 to 3 µm fabricated on sapphire substrates, representing one of the shortest-wavelength realizations of microdisk lasers on this technologically relevant platform. The minimum threshold energy was 8.8 pJ (power density ≈ 280 kW/cm2) for a microlaser with a ...
Added: April 18, 2026
A. V. Pereskokov, Theoretical and Mathematical Physics 2026 Vol. 226 No. 3 P. 470–484
We consider the spectral problem for a hydrogen atom in orthogonal electric and magnetic fields with
an additional self-consistent field. We obtain an asymptotic expansion of self-consistent energy levels.
We find an asymptotic expansion of asymptotic eigenfunctions near the sphere |q| = 2. We calculate the
asymptotics of their norm in the space L2(R3). ...
Added: April 12, 2026
Gabdullin N., Androsov I., / Series Computer Science "arxiv.org". 2026.
Label prediction in neural networks (NNs) has O(n) complexity proportional to the number of classes. This holds true for classification using fully connected layers and cosine similarity with some set of class prototypes. In this paper we show that if NN latent space (LS) geometry is known and possesses specific properties, label prediction complexity can ...
Added: April 2, 2026
Suleymanov I., Вестник Московского университета. Серия 25: Международные отношения и мировая политика 2025 Т. 17 № 4 С. 55–88
The Joint Institute for Nuclear Research (JINR) is an international intergovernmental organization representing a unique research center, whose activities encompass the broadest spectrum of nuclear science. The formation and development of JINR are covered in dozens, if not hundreds, of books and articles published over the institute’s 70-year history. However, the process of its creation ...
Added: January 28, 2026
Sorokin K., Beketov M., Онучин А. et al., / arxiv.org. Серия cs.SI "Social and Information Networks ". 2025.
Community detection in complex networks is a fundamental problem, open to new approaches in various scientific settings. We introduce a novel community detection method, based on Ricci flow on graphs. Our technique iteratively updates edge weights (their metric lengths) according to their (combinatorial) Foster version of Ricci curvature computed from effective resistance distance between the ...
Added: January 15, 2026
Petrovanov I., Sergeev A., / Series Computer Science "arxiv.org". 2025. No. 2512.18332.
Transport coding reduces message delay in packet-switched networks by introducing controlled redundancy at the transport layer: original packets are encoded into coded packets, and the message is reconstructed after the first successful deliveries, effectively shifting latency from the maximum packet delay to the -th order statistic. We present a concise, reproducible discrete-event implementation of transport coding in OMNeT++, including ...
Added: December 24, 2025
Hessian-based lightweight neural network for brain vessel segmentation on a minimal training dataset
Меньшиков И. А., Бернадотт А. К., Elvimov N. S., / Series arXie "Statistical mechanics". 2025.
Accurate segmentation of blood vessels in brain magnetic resonance angiography (MRA) is essential for successful surgical procedures, such as aneurysm repair or bypass surgery. Currently, annotation is primarily performed through manual segmentation or classical methods, such as the Frangi filter, which often lack sufficient accuracy. Neural networks have emerged as powerful tools for medical image ...
Added: December 1, 2025
Чернышов Д. П., Satanin A., Shchur L., / Series arXiv "math". 2025.
We investigate the boundary separating regular and chaotic dynamics in the generalized Chirikov map, an extension of the standard map with phase-shifted secondary kicks. Lyapunov maps were computed across the parameter space (K,K(α, τ)) and used to train a convolutional neural network (ResNet18) for binary classification of dynamical regimes. The model reproduces the known critical ...
Added: November 21, 2025
Rubchinskiy A., Chubarova D., / Series WP7 "Математические методы анализа решений в экономике, бизнесе и политике". 2025. No. WP7/2025/01.
The article examines one of the most famous examples of socio-economic systems, characterized by significant uncertainty – the S&P-500 stock market, where shares of 500 largest US companies are traded. No assumptions are made about the probabilistic characteristics of the stock market. A flexible algorithm for daily trading has been developed, based on both known fixed data ...
Added: November 9, 2025