Mjerenje linearne polarizacije realnih fotona

A survey of known methods of analyzing linear polarization of high-energy photons is presented. The methods of pair photoproduction in single crystals and in amorphous targets are briefly discussed. The method of measurement of photon linear polarization using azimuthal asymmetry of the recoil electrons from pair photoproduction on electron (triplet photoproduction process) is considered in details. The optimum region of kinematic parameters of emitted particles in which analyzing power increases is discussed. Possibility of using CLAS for the measurement of linear photon polarization by analyzing the recoil-electron distribution in triplet photoproduction process (when shielding magnet is turned off) is considered.Daje se pregled poznatih metoda za određivanje linearne polarizacije visokoenergijskih fotona. Raspravlja se kratko tvorba parova u monokristalima i amorfnim metama. Podrobno se razmatra metoda mjerenja polarizacije određivanjem azimutalne asimetrije elektrona od fototvorbe na elektronima (trojna fototvorba). Raspravlja se najpovoljnije područje kinematičkih parametara izlaznih čestica. Izlaže se mogćcnost primjene CLASa za određivanje linearne polarizacije fotona mjerenjem raspodjele odbijenih elektrona iz trojnog fototvorbenog procesa (za vrijeme mjerenja CLASov magnet bi se isključio)

Charged pair production by photon scattering on a proton

We have investigate the production of lepton and pseudoscalar meson charged pairs by high energy linearly polarized photon–proton scattering in the point–like approximation. The corresponding azimuthal and polar angle distributions on a recoil proton in the inclusive experimental setup have been calculated. The asymmetry Λtot has the values from 0.02 at small values of the polar angle θ up to 0.05 for θ ∼ π/2

SCIENTIFIC AND METHODICAL APPROACHES TO INCREASE PROSPECTING EFFICIENCY OF THE RUSSIAN ARCTIC SHELF STATE GEOLOGICAL MAPPING

A rationale for the set of theoretical and methodological techniques of mapping and deep modeling in the Russian Arctic shelf and adjacent sedimentary basins in continental Russia is based on the materials for the Barents and Kara Seas region. This article provides the factual basis of the research and shows how to apply zonal-block model of the crust and generalized models of geodynamic settings in terms of the different geophysical data inconsistency. The necessity and approach for global and regional paleo-reconstructions are also discussed. It is shown that localization of the principal structural and compositional units of the lithosphere being a consequence of geodynamic processes at the boundaries of lithospheric plates, form at the basis of sedimentary cover and crystalline basement layered maps as well as cross-sections of the continental crust. The identified parameters of the deep structure and milestones of the regional tectonic history open new opportunities to explore the regularities of ore deposits distribution. The shown example of the forecast and metallogeny problems solution within Western Siberia and Khatanga-Vilyui petroleum provinces is made using the parameters of known industrial oil and gas fields for training the pattern recognition system

Discovery of an unusual bright eclipsing binary with the longest known period: TYC 2505-672-1 / MASTER OT J095310.04+335352.8

We report on the MASTER Global Robotic Net discovery of an eclipsing binary, MASTER OT J095310.04+335352.8, previously known as unremarkable star TYC 2505-672-1, which displays extreme orbital parameters. The orbital period P=69.1 yr is more than 2.5 times longer than that of epsilon-Aurigae, which is the previous record holder. The light curve is characterized by an extremely deep total eclipse with a depth of more than 4.5 mag, which is symmetrically shaped and has a total duration of 3.5 yrs. The eclipse is essentially gray. The spectra acquired with the Russian 6 m BTA telescope both at minimum and maximum light mainly correspond to an M0-1III--type red giant, but the spectra taken at the bottom of eclipse show small traces of a sufficiently hot source. The observed properties of this system can be better explained as the red giant eclipsed by a large cloud (the disk) of small particles surrounding the invisible secondary companion.Comment: 8 figures, 9 pages, Astronomy and astrophysics in prin

Possible Method for Measuring the Proton Form Factors in Processes with and without Proton Spin Flip

The ratio of the squares of the electric and magnetic proton form factors is shown to be proportional to the ratio of the cross sections for the elastic scattering of an unpolarized electron on a partially polarized proton with and without proton spin flip. The initial proton at rest should be polarized along the direction of the motion of the final proton. Similar results are valid for both radiative $ep$ scattering and the photoproduction of pairs on a proton in the Bethe--Heitler kinematics. When the initial proton is fully polarized in the direction of the motion of the final proton, the cross section for the $ep \to ep$ process, as well as for the $ep \to ep \gamma$ and $\gamma p \to e \bar e p$ processes, without (with) proton spin flip is expressed only in terms of the square of the electric (magnetic) proton form factor. Such an experiment on the measurement of the cross sections without and with proton spin flip would make it possible to acquire new independent data on the behavior of $G_E^2(Q^2)$ and $G_M^2(Q^2)$, which are necessary for resolving the contradictions appearing after the experiment of the JLab collaboration on the measurement of the proton form factors with the method of polarization transfer from the initial electron to the final proton.Comment: 7 pages, revtex

Септическая эмбологенная пневмония при инфекционном эндокардите правых отделов сердца: лучевая диагностика

Early and correct diagnosis of infective endocarditis (ie) of the right heart does not lose its importance due to the persistence of the problem of intravenous drug use and an increase in the number of surgical interventions on the heart. Septic pulmonary embolism (spe) is a typical sign of right-side ie, and, with a number of nonspecific respiratory symptoms in patients with fever, its detection by radiology allows to start a diagnostic search for ie and locate the primary embolic source in the right parts of the heart. The review examines the current state of the problem of right-side ie, morphology and clinical evidence, main ct signs and differential diagnostics of spe, including the context of the covid-19 pandemic.Ранняя и правильная диагностика инфекционного эндокардита (ИЭ) правых отделов сердца не теряет своей важности из-за сохранения проблемы инъекционной наркомании и увеличения количества хирургических вмешательств на сердце. Септическая эмбологенная пневмония (СЭП) является своеобразной «визитной карточкой» правостороннего эндокардита, и именно ее выявление по данным лучевой диагностики при ряде неспецифических респираторных симптомов у больных с лихорадкой позволяет начать диагностический поиск ИЭ и выйти на локализацию первичного эмбологенного источника в правых отделах сердца. В обзоре рассмотрены современное состояние проблемы ИЭ правых отделов сердца, морфологическая и клиническая картина, основные КТ-симптомы и дифференциальная диагностика СЭП, в том числе в условиях пандемии COVID-19

ЭВОЛЮЦИЯ ИЗМЕНЕНИЙ В ЛЕГКИХ ПО ДАННЫМ КТ ПРИ ДИНАМИЧЕСКОМ НАБЛЮДЕНИИ ПАЦИЕНТОВ С COVID-19 В РАННИЕ СРОКИ

The aim of the study: to identify the main variants of CT-symptoms («scenarios») which are observed in patients with COVID-19 viral lung damage with positive clinical course.Materials and methods. We considered follow-up CT data of patients with SARS-nCoV-2 virus infection (confirmed by PCR) with a difference of 5 to 21 days with a positive clinical course of the disease. In some cases, a correlation with morphological data was made.Results. There were identified 5 main «scenarios» for viral lung damage course in COVID-19 (from  complete regression of opacities or minimal residual reticular structures to the phenomena of organization,  atelectasises and initial signs of fibrosis).Conclusions. Understanding of follow-up CT pattern in COVID-19 helps to make a decision at an early stage about necessity for additional therapy, which allows to avoid potentially possible fibrotic lung process in the future.Цель: выделить основные варианты КТ-картины («сценарии»), которые наблюдаются при положительной динамике вирусного поражения легких у больных с COVID-19.Материалы и методы. Рассмотрены КТ-данные пациентов с подтвержденной вирусной инфекцией SARS-nCoV-2 (ПЦР) в динамике с разницей от 5 до 21 дня при положительном клиническом течении заболевания, выполненных за время работы в COVID-центрах г. Москвы. В части случаев проведена корреляция с морфологическими данными.Результаты. Были выделены 5 основных «сценариев», по которым происходит разрешение вирусного поражения легких при коронавирусной инфекции (от полного регресса уплотнений или минимальных остаточных изменений до явлений организации,  ателектазирования и начальных признаков фиброза).Заключение. Понимание КТ-картины в динамике при COVID-19 помогает уже на ранних этапах принять решение о необходимости применения дополнительной терапии, позволяющей в дальнейшим избежать потенциально возможных фиброзных изменений в легких