A coupled-channel analysis of BESIII data on radiative J/ψ decays into ππ, KK¯, ηη and ωϕ has been performed. The partial-wave amplitude is constrained by a large number of further data. The analysis ...finds ten isoscalar scalar mesons. Their masses, widths and decay modes are determined. The scalar mesons are interpreted as mainly SU(3)-singlet and mainly octet states. Octet isoscalar scalar states are observed with significant yields only in the 1500-2100MeV mass region. Singlet scalar mesons are produced over a wide mass range but their yield peaks in the same mass region. The peak is interpreted as scalar glueball. Its mass and width are determined to M=1865±25−30+10MeV and Γ=370±50−20+30MeV, its yield in radiative J/ψ decays to (5.8±1.0)10−3.
Search for the tensor glueball Klempt, E.; Nikonov, K.V.; Sarantsev, A.V. ...
Physics letters. B,
07/2022, Letnik:
830
Journal Article
Recenzirano
Odprti dostop
The tensor glueball is searched for in BESIII data on radiative J/ψ decays into π0π0 and KsKs. The ππ invariant mass distribution exhibits an enhancement that can be described by a pole at ...(2210±60)−i(180±60)MeV or by three of ϕϕ resonances suggested a long time ago to be the trace of one, two or three glueballs. We speculate that several high-mass tensor mesons might have qq¯ and glueball components.
The features of the formation of a hidden lead-silicate insulating layer in silicon substrates are considered. To do this, ions of molecular oxygen and lead are sequentially implanted into them in an ...atomic ratio of 75 : 1 then annealing is carried out at a temperature of 1150°C in an environment of dry oxygen. The distribution of the implanted ions in the experimental samples is recorded by the method of secondary ion mass spectrometry. It is shown that the latent insulator is formed in the process of the spinodal decomposition of a solid solution of SiO
x
–PbO
x
in the form of a three-layer structure. Its middle part is silicon dioxide doped with lead ions and the side parts consist of a lead-silicate phase. A relaxation diffusion model is proposed to analyze the distribution profile of lead.
The Spin Physics Detector (SPD) is a future multipurpose experiment foreseen to run at the NICA collider, which is currently under construction at the Joint Institute for Nuclear Research (JINR, ...Dubna, Russia). The physics program of the experiment is based on collisions of longitudinally and transversely polarized protons and deuterons at s up to 27 GeV and luminosity up to 1032 cm−2 s−1. SPD will operate as a universal facility for the comprehensive study of the unpolarized and polarized gluon content of the nucleon, using complementary probes such as: charmonia, open-charm, and prompt-photon production processes.
The aim of this work is to provide a thorough review of the physics objectives that can potentially be addressed at SPD, underlining related theoretical aspects and discussing relevant experimental results when available. Among different pertinent phenomena particular attention is drawn to the study of the gluon helicity, gluon Sivers and Boer-Mulders functions in the nucleon, as well as the gluon transversity distribution in the deuteron, via the measurement of single and double spin asymmetries.
—
This review presents promising developments in the use of thermomigration processes to form doped or compositionally modified regions in various semiconductor materials. Methods of capillary ...formation of flat liquid zones of various compositions, migration of eutectic droplets under pulsed action of electric and temperature fields, and migration of droplets along the atomically clean surface of semiconductors are considered. The use of these methods makes it possible to expand the dimensional limits of device formation over a wide range from centimeter to nanometer scales. New developments in the field of photonics are also presented. The proposed method of recrystallization of silicon fiber core using CO
2
laser scanning was combined with thermal migration of melt zone of different composition. This makes it possible to improve the microstructure of core material and form light-emitting GaSb inclusions (and even a Si-GaSb heterostructures) inside the optical fiber. Such integration of semiconductor materials, embedded in the geometry of the optical fiber, is very relevant when creating integrated systems of biomedicine or photon conversion of solar energy.
Identifying low-dimensional features that describe large-scale neural recordings is a major challenge in neuroscience. Repeated temporal patterns (sequences) are thought to be a salient feature of ...neural dynamics, but are not succinctly captured by traditional dimensionality reduction techniques. Here, we describe a software toolbox-called seqNMF-with new methods for extracting informative, non-redundant, sequences from high-dimensional neural data, testing the significance of these extracted patterns, and assessing the prevalence of sequential structure in data. We test these methods on simulated data under multiple noise conditions, and on several real neural and behavioral datas. In hippocampal data, seqNMF identifies neural sequences that match those calculated manually by reference to behavioral events. In songbird data, seqNMF discovers neural sequences in untutored birds that lack stereotyped songs. Thus, by identifying temporal structure directly from neural data, seqNMF enables dissection of complex neural circuits without relying on temporal references from stimuli or behavioral outputs.
Behaviors emerge via a combination of experience and innate predispositions. As the brain matures, it undergoes major changes in cellular, network, and functional properties that can be due to ...sensory experience as well as developmental processes. In normal birdsong learning, neural sequences emerge to control song syllables learned from a tutor. Here, we disambiguate the role of tutor experience and development in neural sequence formation by delaying exposure to a tutor. Using functional calcium imaging, we observe neural sequences in the absence of tutoring, demonstrating that tutor experience is not necessary for the formation of sequences. However, after exposure to a tutor, pre-existing sequences can become tightly associated with new song syllables. Since we delayed tutoring, only half our birds learned new syllables following tutor exposure. The birds that failed to learn were the birds in which pre-tutoring neural sequences were most 'crystallized,' that is, already tightly associated with their (untutored) song.
Ion synthesis of silicon-on-insulator structures based on successive implantation of oxygen ions and a glass former into silicon substrates has been investigated. Lead ions are used as a ...glass-former. Specific features of formation of a buried silicate layer upon postimplantation annealing are considered. Current–voltage characteristics of the synthesized structures and resistivities of the insulator and the silicon device layer are measured.
Data on the reaction γp→ωp with ω→π0γ, taken with unpolarized or polarized beams in combination with an unpolarized or polarized proton-target, were analyzed within the Bonn–Gatchina (BnGa) partial ...wave analysis. Differential cross sections, several spin density matrix elements, the beam asymmetry Σ, the normalized helicity difference E, and the correlation G between linear photon and longitudinal target polarization were included in a large data base on pion and photo-induced reactions. The data on ω photoproduction are used to determine twelve N⁎→Nω branching ratios; most of these are determined for the first time.
PDF
