Infinite (continuous) spin fields in the frame-like formalism

In this paper we elaborate on the gauge invariant frame-like Lagrangian description for the wide class of the so-called infinite (or continuous) spin representations of Poincar\'e group. We use our previous results on the gauge invariant formalism for the massive mixed symmetry fields corresponding to the Young tableau with two rows Y(k,l) (Y(k+1/2,l+1/2) for the fermionic case). We have shown that the corresponding infinite spin solutions can be constructed as a limit where k goes to infinity, while l remain to be fixed and label different representations. Moreover, our gauge invariant formalism provides a natural generalization to (Anti) de Sitter spaces as well. As in the completely symmetric case considered earlier by Metsaev we have found that there are no unitary solutions in de Sitter space, while there exists a rather wide spectrum of Anti de Sitter ones. In this, the question what representations of the Anti de Sitter group such solutions correspond to remains to be open.Comment: 37 pages, 6 figure

Optical and transport properties of short period InAs/GaAs superlattices near quantum dot formation

We have investigated the optical and transport properties of MBE grown short-period superlattices of InAs/GaAs with different numbers of periods (3 <= N <= 24) and a total thickness 14 nm. Bandstructure calculations show that these superlattices represent a quantum well with average composition In_0.16Ga_0.84As. The electron wave functions are only slightly modulated by the superlattice potential as compared to a single quantum well with the same composition, which was grown as a reference sample. The photoluminescence, the resistance, the Shubnikov-de Haas effect and the Hall effect have been measured as a function of the InAs layer thickness Q in the range 0.33 <= Q <= 2.7 monolayers (ML). The electron densities range from 6.8 to 11.5x10^11 cm^-2 for Q <= 2.0 ML. The photoluminescence and magnetotransport data show that only one subband is occupied. When Q >= 2.7 ML quantum dots are formed and the metallic type of conductivity changes to variable range hopping conductivity.Comment: 15 pages (incl.7 figures); pdf file; submitted to Semicond. Sci. Techno

On the K^+D Interaction at Low Energies

The Kd reactions are considered in the impulse approximation with NN final-state interactions (NN FSI) taken into account. The realistic parameters for the KN phase shifts are used. The "quasi-elastic" energy region, in which the elementary KN interaction is predominantly elastic, is considered. The theoretical predictions are compared with the data on the K^+d->K^+pn, K^+d->K^0pp, K^+d->K^+d and K^+d total cross sections. The NN FSI effect in the reaction K^+d->K^+pn has been found to be large. The predictions for the Kd cross sections are also given for slow kaons, produced from phi(1020) decays, as the functions of the isoscalar KN scattering length a_0. These predictions can be used to extract the value of a_0 from the data.Comment: 22 pages, 5 figure

Успешное лечение тяжелого течения коронавирусной инфекции у поликоморбидного пациента с ожирением после бариатрической операции

We presented a clinical case of the successful treatment of a severe course of polysegmental pneumonia caused by the novel coronavirus infection, that developed in the postoperative period after bariatric surgery in the patient with morbid obesity, comorbid type 2 diabetes mellitus, ischemic heart disease, arterial hypertension, pulmonary embolism (in past medical history), and stage 3 chronic obstructive pulmonary disease. The given clinical case demonstrates the possibility of successful treatment of coronavirus infection in the polymorbid patient at an extremely high risk of an unfavorable outcome, given timely diagnosis, combination therapy using drugs that block cytokine storm, and strict adherence to clinical recommendations.Представлено клиническое наблюдение успешного лечения тяжелого течения полисегментарной пневмонии коронавирусной этиологии, развившейся в послеоперационном периоде бариатрической операции у пациента с морбидным ожирением, сопутствующим сахарным диабетом 2-го типа, ишемической болезнью сердца, гипертонической болезнью, тромбоэмболией мелких ветвей легочной артерии в анамнезе, хронической обструктивной болезнью легких 3-й степени. Приведенный клинический случай демонстрирует возможность успешного лечения коронавирусной инфекции у поликоморбидного пациента с крайне высоким риском неблагоприятного исхода при условии своевременной диагностики, комплексного лечения с использованием препаратов, блокирующих цитокиновый шторм, и строгого выполнения клинических рекомендаций.

Triple GEM Tracking Detectors for the BM@N Experiment

BM@N (Baryonic Matter at the Nuclotron) is the fixed target experiment aimed to study nuclear matter in the relativistic heavy ion collisions at the Nuclotron accelerator in JINR. The BM@N tracking system is based on Gas Electron Multipliers (GEM) detectors, mounted inside the BM@N analyzing magnet. The structure of the GEM detectors and the results of study of their characteristics are presented. The GEM detectors are integrated into the BM@N experimental setup and data acquisition system. The results of the first test of the GEM tracking system in the technical run with the deuteron beam are shortly reviewed