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First Measurement of the B+ → π + π0π0 Branching Fraction and CP Asymmetry
Physical Review Letters. 2023. Vol. 130. No. 18. Article 181804.
Lai Y. -., Adachi I., Aihara H., Al Said S., Asner D. M., Atmacan H., Aulchenko V., T. Aushev, G. Pakhlova, T. Uglov
We study B+→π+π0π0 using 711 fb−1 of data collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. We measure an inclusive branching fraction of (19.0±1.5±1.4)×10−6 and an inclusive CP asymmetry of (9.2±6.8±0.7)%, where the first uncertainties are statistical and the second are systematic, and a B+→ρ(770)+π0 branching fraction of (11.2±1.1±0.9+0.8−1.6)×10−6, where the third uncertainty is due to possible interference with B+→ρ(1450)+π0. We present the first observation of a structure around 1 GeV/c2 in the π0π0 mass spectrum, with a significance of 6.4σ, and measure a branching fraction to be (6.9±0.9±0.6)×10−6. We also report a measurement of local CP asymmetry in this structure.
Войтович В. И., Makhov I., Andryushkin V. V. et al., Journal of Luminescence 2026 Vol. 295 Article 121936
We report on a comparative study of the optical and structural properties of short-period superlattices (SPSLs) based on digital ternary InGaAs/InAlAs alloys and their counterparts with quaternary InGaAlAs barriers, both grown on InP substrates and emitting in the 1.3 μm wavelength range. The heterostructures were grown by molecular beam epitaxy and analyzed using photoluminescence spectroscopy ...
Added: July 8, 2026
Babichev A., Bobrov M., Vasil'ev A. et al., Applied Physics Letters 2026 Vol. 128 Article 241102
High-quality planar cavities with low-absorption mirrors based on Al0.2Ga0.8As/Al0.9Ga0.1As layers demonstrate continuous wave lasing at a wavelength of 956 nm. At 300 K, the threshold power density and the quality-factor at the threshold are 4.2 kW/cm2 and 6800. Increasing the pump level above two thresholds results in an enlargement in the quality-factor to at least 19 ...
Added: July 8, 2026
Pilé I., Shchur L., Deng Y., Physical Review B: Condensed Matter and Materials Physics 2026 Vol. 114 Article 014101
We investigate the spatial overlap of successive spin configurations in Markov chain Monte Carlo simulations using the local Metropolis algorithm and the Swendsen-Wang and Wolff cluster algorithms. We examine the dynamics of these algorithms for models in different universality classes: Ising model, Potts model with three components, and four-state Potts model. The overlap of two ...
Added: July 6, 2026
МФТИ, 2025.
абота редакции научного журнала «Труды Московского физико-технического института» (кратко «Труды МФТИ»), редакционной коллегии и редакционного совета осуществляется в соответствии с Положением, утвержденным ректором института. В состав редакционной коллегии входят руководители института, факультетов, институтских и факультетских кафедр. Главный редактор журнала —президент МФТИ, член-корр. РАН Кудрявцев Н.Н.
Журнал «Труды МФТИ» входит в базу данных РИНЦ (Российский Индекс Научного Цитирования) и доступен в электронной ...
Added: July 4, 2026
Bobkov G. A., Bobkov G. A., Bobkova I. V. et al., Journal of Superconductivity and Novel Magnetism 2025 Vol. 38 Article 239
In recent years, a number of studies have predicted the emergence of a nontrivial proximity effect in superconductor/antiferromagnet (S/AF) heterostructures. This effect is of considerable interest for the efficient integration of antiferromagnetic materials into the fields of superconducting spintronics and electronics. A key element of this proximity effect is the Néel triplet correlations, initially predicted ...
Added: July 2, 2026
Bakurskiy S. V., Skryabina O. V., Ruzhickiy V. I. et al., Physical Review B: Condensed Matter and Materials Physics 2026 Vol. 113 P. 134509-1–134509-10
The miniaturization of superconducting electronics demands precise control over quasiparticle dynamics at the nanoscale. Understanding and controlling quasiparticle dynamics is essential for advancing superconducting electronics, particularly as device dimensions approach the nanoscale. Here we present direct experimental evidence for the quasiparticle-to-supercurrent conversion in planar SN-N-NS Josephson nanobridges with submicron electrodes. By employing a versatile measurement ...
Added: July 2, 2026
Polevoy K. B., Bakurskiy S. V., Ruzhickiy V. I. et al., Physical Review Applied 2026 Vol. 25 P. 024030-1–024030-12
We present a comprehensive study of planar Nb-Al-Nb Josephson junctions with submicrometer dimen sions (L ≈ 100 nm, active area of approximately 5 × 104 nm2), where the intrinsic superconductivity of the aluminum weak link plays a crucial role in enhancing device performance. Through a combi nation of theoretical modeling and experimental characterization, we demonstrate ...
Added: July 2, 2026
Никонов В. Д., Никитин С. С., Патракеев М. В., Ionics 2025 Vol. 31 No. 1 P. 675–687
Modification of perovskite-type oxides is an effective way to develop functional materials with advanced properties. The effects of cerium introduction into the A sublattice of La0.5Sr0.5FeO3−δ and variation of La:Sr ratio on the defect structure and charge transfer characteristics were studied in this work. The LaxSr0.85−xCe0.15FeO3−δ oxides were found to be single-phase with cubic (x = 0.1) and orthorhombic ...
Added: June 26, 2026
Polkin A., Skvortsov M., Physical Review B: Condensed Matter and Materials Physics 2026 Vol. 113 Article 174516
We develop a full microscopic theory for the optical conductivity 𝜎(𝜔) of a dirty current-carrying superconductor. Within the Keldysh sigma model formalism, we obtain the general analytical expression for 𝜎(𝜔), applicable for arbitrary frequency 𝜔, temperature 𝑇, and dc supercurrent 𝐼. In addition to altering the usual Mattis-Bardeen conductivity 𝜎1(𝜔), a finite supercurrent introduces two new contributions: 𝜎qp2(𝜔) from quasiparticle redistribution and 𝜎SH2(𝜔) from the amplitude ...
Added: June 25, 2026
Skvortsov M., Artem V. Polkin, Physical Review B: Condensed Matter and Materials Physics 2026 Vol. 113 No. 10 Article L100502
A dissipationless supercurrent state in superconductors can be destroyed by thermal fluctuations. Thermally activated phase slips provide a finite resistance of the sample and are responsible for dark counts in superconducting single-photon detectors. The activation barrier for a phase slip is determined by a space-dependent saddle-point (instanton) configuration of the order parameter. In the one-dimensional ...
Added: June 25, 2026
Деменев А. А., Терешко С. Н., Гиппиус Н А et al., Известия РАН. Серия физическая 2025 Т. 89 № 2 С. 265–273
The authors study the temporal evolution of polarized spectra of emissions from spinor exciton‒
polariton condensates in double tunnel-coupled potential traps inside a high-Q GaAs/AlAs microcavity
at 2 K upon resonance laser pumping with picosecond pulses at times of up to 1.5 ns. The period of the condensates’
spin relaxation in a double trap is estimated as τs ...
Added: June 23, 2026
Абрамов-Максимов В. Е., И.А. Бакунина, Геомагнетизм и аэрономия 2026 Т. 66 № 3 С. 515–529
Проанализировано 8 вспышечных событий по данным многочастотных наблюдений сети радиотелескопов Radio Solar Telescope Network. Целью анализа было выявление предвестников солнечных вспышек. В семи рассмотренных случаях выявлены предвспышечные квазипериодические флуктуации радиоизлучения. Сделанная по вейвлет-спектрам оценка квазипериодов дает в большинстве случаев значения 40–50 сек. В одном событии с большой вспышкой класса M8.0 квазипериодические флуктуации не проявились. В ...
Added: June 22, 2026
И.А. Бакунина, В.Ф. М., А.В. Ш. et al., Геомагнетизм и аэрономия 2025 Т. 65 № 9 С. 1363–1373
Рассмотрена связь особенностей положения и ориентации магнитных жгутов в активной области (АО) с источниками микроволнового (17 ГГц) излучения и излучения в крайнем ультрафиолетовом диапазоне (EUV) при возникновении эруптивных вспышек, сопровождающихся корональными выбросами массы, и вспышек с "запертой" эрупцией. Приведены примеры эруптивных событий, демонстрирующие пространственное совпадение микроволновых источников с расположением магнитных жгутов в АО, восстановленных при ...
Added: June 22, 2026
Г. Г. Бондаренко, Кристя В. И., Савичкин Д. О. et al., Поверхность. Рентгеновские, синхротронные и нейтронные исследования 2026 № 4 С. 29–36
Сформулирована модель тлеющего газового разряда в смеси аргона и паров ртути при наличии
на поверхности катода тонкой диэлектрической пленки. Рассчитаны зависимости характеристик
разряда от температуры в интервале ее изменения, в котором заметный вклад в ионизацию
рабочей газовой смеси дает ионизация атомов ртути метастабильными возбужденными атомами
аргона (реакция Пеннинга). Показано, что в случае катода без диэлектрической пленки при
повышении температуры до ...
Added: June 20, 2026
Chertenkov V. I., Shchur L., Lobachevskii Journal of Mathematics 2026 Vol. 47 No. 2 P. 720–727
Supervised machine learning is successfully applied to the study of critical phenomena and allows us to obtain a numerical estimate of the phase transition temperature and the correlation length exponent. We discuss the influence of possible systematic errors, as well as statistical errors, on the accuracy of such numerical estimates. Errors in the training and ...
Added: June 16, 2026
Батурин А. С., Гаврилов В. Р., Иванов А. В. et al., Измерительная техника 2026 Т. 75 № 2 С. 14–28
28 декабря 2025 года Всероссийскому научно-исследовательскому институту оптико-физических измерений (ВНИИОФИ) исполнилось 60 лет. За прошедшие десятилетия институт выполнил значительное количество научных исследований, разработал и поставил потребителям тысячи высокоточных средств оптико-физических измерений (включая эталонное оборудование). В статье представлены наиболее значимые для метрологического обеспечения оптико-физических измерений результаты научно-исследовательских работ, выполненных ВНИИОФИ за период 2016–2025 гг. ...
Added: June 15, 2026
Вишняков Г. Н., Левина Э. Ю., Minaev V., Измерительная техника 2025 Т. 74 № 2 С. 20–27
Качество формируемого оптической системой изображения определяется её частотно-контрастной характеристикой или коэффициентами передачи модуляции на различных пространственных частотах. Для обеспечения единства измерений коэффициентов передачи модуляции и создания эталонной базы по воспроизведению, хранению и передаче единицы коэффициента передачи модуляции усовершенствован Государственный первичный эталон единиц оптической силы очковой оптики ГЭТ 205-2013 в части воспроизведения единицы коэффициентов передачи модуляции ...
Added: June 15, 2026
Filippova A. V., Yurchenko N. Y., Smirnov S. A. et al., Journal of Alloys and Compounds 2026 No. 1074 Article 189162
This study investigates the effects of post-processing heat treatment at 300–500 °C on the microstructure, hardness, and tensile properties of laser powder bed fusion (PBF-LB) processed Al-bronze processed with energy densities (ED) in the range of 125–938 J/mm3. In the as-printed state, sharp needle-like α + β′ laths form at lower ED whereas with increasing ED, the β′ ...
Added: June 12, 2026
Aaij R., Abdelmotteleb A. S., Abellan Beteta C. et al., Journal of High Energy Physics 2024 Vol. 2024 No. 2 Article 173
A study of Bc+→χcπ+ decays is reported using proton-proton collision data, collected with the LHCb detector at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9 fb−1. The decay Bc+→χc2π+ is observed for the first time, with a significance exceeding seven standard deviations. The relative branching fraction with respect to the Bc+→J/ψπ+ decay is measured ...
Added: September 17, 2024
Aaij R., Abdelmotteleb A. S., Abellan Beteta C. et al., Journal of High Energy Physics 2024 Vol. 2024 No. 5 Article 293
Measurements of the branching fraction ratio B(ϕ→μ+μ−)/B(ϕ→e+e−) with Ds+→π+ϕ and D+ → π+ϕ decays, denoted Rϕπs and Rϕπd, are presented. The analysis is performed using a dataset corresponding to an integrated luminosity of 5.4 fb−1 of pp collision data collected with the LHCb experiment. The branching fractions are normalised with respect to the B+ → K+J/ψ(→ e+e−) and B+ → K+J/ψ(→ μ+μ−) decay modes. The combination of the results yields
Rϕπ=1.022±0.012(stat)±0.048(syst).
The result is compatible with previous measurements ...
Added: September 17, 2024
Kinoshita K., Aihara H., Aushev T. et al., Science Bulletin 2023
We report a study of Λ+c→Λh+ and Λ+c→Σ0h+ (h=K,π) decays based on a data sample of 980~fb−1 collected with the Belle detector at the KEKB energy-asymmetric e+e− collider. The first results of direct CP asymmetry in two-body singly Cabibbo-suppressed (SCS) decays of charmed baryons are measured, AdirCP(Λ+c→ΛK+)=+0.021±0.026±0.001 and AdirCP(Λ+c→Σ0K+)=+0.025±0.054±0.004. We also make the most precise measurement of the decay asymmetry parameters (α) for the four modes of ...
Added: December 1, 2023
Chang C. -., Wang M. -., Adachi I. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2023 Vol. 108 No. 5 Article 052011
We search for the B0→p¯Σ0π− decay with ¯Σ0→¯Λγ, where the γ is not measured, using a data sample corresponding to an integrated luminosity of 711 fb−1 which contains 772×106 B¯B pairs, collected around the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. We measure for the first time the B0→p¯Σ0π− branching fraction to be B(B0→p¯Σ0π−)=(1.17+0.43−0.40(stat)±0.07(syst))×10−6 with a significance of 3.0σ. We simultaneously measure the branching fraction for the related channel B0→p¯Λπ− with much ...
Added: December 1, 2023
Hsu C. -., Sevior M. E., Adachi I. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2023 Vol. 107 No. 3 Article 032013
We study the decay B+→K+K−π+ and investigate the angular distribution of K+K− pairs with invariant mass below 1.1 GeV/c2. This region exhibits both a strong enhancement in signal and very large direct CP violation. We construct a coherent sum model for the angular distribution of S- and P-wave, and report the ratio of their amplitudes, the relative phase and the forward-backward asymmetry. We also report ...
Added: December 1, 2023
Teramoto Y., Uehara S., Adachi I. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2023 Vol. 108 No. 1 Article 012004
We report the first measurement of the Q2 distribution of X(3915) produced by single-tag two-photon interactions. The decay mode used is X(3915)→J/ψω. The covered Q2 region is from 1.5 (GeV/c)2 to 10.0 (GeV/c)2. We observe 7.9±3.1(stat.)±1.5(syst.) events, where we expect 4.1±0.7 events based on the Q2=0 result from the no-tag two-photon process, extrapolated to higher Q2 region using the cc¯ model of Schuler, Berends, and van Gulik. The shape of the distribution is ...
Added: November 30, 2023