Weak productions of new charmonium in semi-leptonic decays of B_c

We study the weak productions of novel heavy mesons, such as $\eta_c^{\prime}$, $h_c$, $h_c^{\prime}$, $\chi_{c0}^{\prime}$, X(3940), Y(3940), X(3872), and Y(4260), in the semi-leptonic $B_c$ decays. Since there is still no definite answer for the components of X(3940), Y(3940), X(3872), Y(4260) so far, we will assign them as excited charmonium states with the possible quantum numbers constrained by the current experiments. As for the weak transition form factors, we calculate them in the framework of light-cone QCD sum rules approach, which is proved to be a powerful tool to deal with the non-perturbative hadronic matrix element. Our results indicate that different interpretations of X(3940) can result in remarkable discrepancy of the production rate in the $B_c$ decays, which would help to clarify the inner structure of the X(3940) with the forthcoming LHC-b experiments. Besides, the predicted large weak production rates of X(3872) and Y(3940) in $B_c$ decays and the small semi-leptonic decay rate for $B_c \to Y(4260)$ all depend on their quantum number $J^{PC}$ assignments. Moreover, the $S-D$ mixing of various vector charmonium states in the weak decay of $B_c$ is also discussed in this work. The future experimental measurements of these decays will test the inner structures of these particles, according to our predictions here.Comment: 26 pages, with 7 figures, revTex

Perturbative QCD of hard and soft processes

We discuss some problems concerning the application of perturbative QCD to high energy processes. In particular for hard processes, we analyze higher order and higher twist corrections. It is argued that these effects are of great importance for understanding the behaviour of pion electromagnetic form factor at moderately large momentum transfers. For soft processes, we show that summing the contributions of the lowest twist operators leads to a Regge-like amplitude.Comment: Reproduction of unpublished JINR Report E2-80-521, Dubna 1980. 22 pages 9 figures. To be published in Modern Physics Letters A. Style file is include

Professional Doctorates: International Experience and Russian Context

The diversification of forms and types of doctoral programs is currently a global trend. Universities across the globe offer programs that differ in the modes of training, characteristics of the target audience, and possible labor markets after graduation. In Russia, doctoral education exists in a unified format, focusing primarily on the academic labor market. Recently, there have been discussions about the need to expand the range of programs and the types of academic degrees in Russia. In this article, we present the analysis of professional doctoral programs: in response to what challenges and needs they appeared, how they are implemented, in what forms they exist. In addition, we consider the Russian experience of implementing professional doctoral programs; analyze the existing opportunities and barriers for their development. Based on the analysis, we came to a conclusion about the relevance of the professional doctoral programs’ development in Russia, the expediency of simplifying the conditions for their implementation and legitimizing special requirements for the design of dissertations with an applied orientation

BG Ind: the nearest doubly eclipsing, compact hierarchical quadruple system

BG Ind is a well-studied, bright, nearby binary consisting of a pair of F stars in a 1.46-d orbit. We have discovered in the TESS light curve for TIC 229804573 (aka BG Ind), a second eclipsing binary in the system with a 0.53-d period. Our subsequent analyses of the recent TESS and archival ground-based photometric and radial velocity (RV) data reveal that the two binaries are gravitationally bound in a 721-d period, moderately eccentric orbit. We present the results of a joint spectro-photodynamical analysis of the eclipse timing variation curves of both binaries based on TESS and ground-based archival data, the TESS light curve, archival RV data, and the spectral energy distribution, coupled with the use of PARSEC stellar isochrones. We confirm prior studies of BG Ind that found that the brighter binary A consists of slightly evolved F-type stars with refined masses of 1.32 and 1.43 M⊙, and radii of 1.59 and 2.34R⊙. The previously unknown binary B has two less massive stars of 0.69 and 0.64 M⊙ and radii of 0.64 and 0.61R⊙. Based on a number of different arguments that we discuss, we conclude that the three orbital planes are likely aligned to within 17○

Radio Galaxy Zoo: discovery of a poor cluster through a giant wide-angle tail radio galaxy

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2016 J. K. Banfield, H. Andernach, A. D. Kapińska, L. Rudnick, M. J. Hardcastle, G. Cotter, S. Vaughan, T. W. Jones, I. Heywood, J. D. Wing, O. I. Wong, T. Matorny, I. A. Terentev, Á. R. López-Sánchez, R. P. Norris, N. Seymour, S. S. Shabala, and K. W. Willett. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. The version of record is available on line at doi: 10.1093/mnras/stw1067We have discovered a previously unreported poor cluster of galaxies (RGZ-CL J0823.2+0333) through an unusual giant wide-angle tail radio galaxy found in the Radio Galaxy Zoo project. We obtained a spectroscopic redshift of $z=0.0897$ for the E0-type host galaxy, 2MASX J08231289+0333016, leading to M$_r = -22.6$ and a $1.4\,$GHz radio luminosity density of $L_{\rm 1.4} = 5.5\times10^{24}$ W Hz$^{-1}$. These radio and optical luminosities are typical for wide-angle tailed radio galaxies near the borderline between Fanaroff-Riley (FR) classes I and II. The projected largest angular size of $\approx8\,$arcmin corresponds to $800\,$kpc and the full length of the source along the curved jets/trails is $1.1\,$Mpc in projection. X-ray data from the XMM-Newton archive yield an upper limit on the X-ray luminosity of the thermal emission surrounding RGZ J082312.9+033301,at $1.2-2.6\times10^{43}$ erg s$^{-1}$ for assumed intra-cluster medium temperatures of $1.0-5.0\,$keV. Our analysis of the environment surrounding RGZ J082312.9+033301 indicates that RGZ J082312.9+033301 lies within a poor cluster. The observed radio morphology suggests that (a) the host galaxy is moving at a significant velocity with respect to an ambient medium like that of at least a poor cluster, and that (b) the source may have had two ignition events of the active galactic nucleus with $10^7\,$yrs in between. This reinforces the idea that an association between RGZ J082312.9+033301, and the newly discovered poor cluster exists.Peer reviewe

Radar Cross Section Measurements Error Reduction by the Interfering Clutter Rejection in an Anechoic Chamber

Поступила: 10.06.2022. Принята в печать: 30.09.2022.Received: 10.06.2022. Accepted: 30.09.2022.Показано влияние помехового сигнала прямого прохождения на ошибки измерения эффективной поверхности рассеяния (ЭПР) объектов. Рассмотрены две основные частные составляющие погрешности измерения ЭПР, на которые оказывает влияние помеховый сигнал прямого прохождения: амплитудная неравномерность электромагнитного поля (ЭМП) и относительный уровень кроссполяризационной развязки. Обоснована целесообразность режекции помехового сигнала прямого прохождения на основе стробирования полезного сигнала в интересах снижения частных составляющих погрешностей измерения ЭПР. На основе экспериментальных данных, полученных в условиях радиолокационного измерительного комплекса (РИК) закрытого типа, продемонстрирована возможность снижения погрешности измерения ЭПР объектов более чем на 10 % в низком диапазоне частот.The influence of the interfering clutter on the radar cross section (RCS) measurements error is demonstrated. Two main partial components of the RCS measurements error are considered: electromagnetic field amplitude irregularity and cross-polarization isolation level. The expediency of the interfering clutter rejection by the planar electromagnetic field signal gating is justified in the partial components of the RCS measurements error reduction purposes. The possibility to reduce RCS measurements error more than 7 percent for the low frequency band based on experimental data, measured in the anechoic chamber conditions is revealed

BG Ind: the nearest doubly eclipsing, compact hierarchical quadruple system

BG Ind is a well-studied, bright, nearby binary consisting of a pair of F stars in a 1.46-d orbit. We have discovered in the TESS light curve for TIC 229804573 (aka BG Ind), a second eclipsing binary in the system with a 0.53-d period. Our subsequent analyses of the recent TESS and archival ground-based photometric and radial velocity (RV) data reveal that the two binaries are gravitationally bound in a 721-d period, moderately eccentric orbit. We present the results of a joint spectro-photodynamical analysis of the eclipse timing variation curves of both binaries based on TESS and ground-based archival data, the TESS light curve, archival RV data, and the spectral energy distribution, coupled with the use of PARSEC stellar isochrones. We confirm prior studies of BG Ind that found that the brighter binary A consists of slightly evolved F-type stars with refined masses of 1.32 and 1.43 M-circle dot, and radii of 1.59 and 2.34 R-circle dot. The previously unknown binary B has two less massive stars of 0.69 and 0.64 M-circle dot and radii of 0.64 and 0.61 R-circle dot. Based on a number of different arguments that we discuss, we conclude that the three orbital planes are likely aligned to within 17 degrees

Neuropsychological evaluation of cognitive disorders in children after COVID-19

The article presents the results of neuropsychological remote and face-to-face testing of 25 children aged 12 to 17 years in the nearest (during and 1-2 weeks after the treatment) and later period (2-12 months) after COVID-19 infection with predominant respiratory tract infection, organized in Ekaterinburg in the State Autonomous Institution "Children's Hospital № 8". Indication of family contact with patients with a new coronavirus infection was found in all patients, a positive nasopharyngeal swab for SARS-CoV-2 RNA by PCR was found in 58%, non-focal neurological complaints were found in 54% of children. The control group consisted of 25 pupils of Moscow comprehensive schools (14 girls and 11 boys) aged between 12 and 16 years who were examined before the pandemic. The methods included: investigation of the kinesthetic, spatial, dynamic, graphic praxis; auditory-motor coordination; visual, object-constructive gnosis; auditory-speech, visual memory; voluntary attention; thinking. Significant differences with the results of neuropsychological tests performed in children in the control group were found, allowing us to assert impairment of memory, attention, visual gnosis, visual-spatial function, kinesthetic and dynamic praxis, verbal and non-verbal component of thinking. According to A.R. Luria's theory, the topic of the disorders involves the temporo-parieto-occipital, mediobasal, frontotemporal parts of the brain, the reticular formation and limbic structures. This necessitates the development of corrective educational programs and an in-depth diagnostic algorithm that determines the morphological substrate of cognitive disorders in children, who have undergone COVID-19. © 2022 PAGEPress Publications. All rights reserved.Ministry of Health of the Russian FederationPirogov Russian National Research Medical University, RNRMUThe study was funded by Pirogov Russian National Research Medical University of the Ministry of Health of the Russian Federation, Moscow