Direct Evidence of Two Superconducting Gaps in FeSe0.5_{0.5}Te0.5_{0.5}: SnS-Andreev Spectroscopy and Lower Critical Field

We present direct measurements of the superconducting order parameter in nearly optimal FeSe$_{0.5}$Te$_{0.5}$ single crystals with critical temperature $T_C \approx 14$ K. Using intrinsic multiple Andreev reflection effect (IMARE) spectroscopy and measurements of lower critical field, we directly determined two superconducting gaps, $\Delta_L \approx 3.3 - 3.4$ meV and $\Delta_S \approx 1$ meV, and their temperature dependences. We show that a two-band model fits well the experimental data. The estimated electron-boson coupling constants indicate a strong intraband and a moderate interband interaction

Three-loop contribution of the Faddeev-Popov ghosts to the β\beta-function of N=1{\cal N}=1 supersymmetric gauge theories and the NSVZ relation

We find the three-loop contribution to the $\beta$-function of ${\cal N}=1$ supersymmetric gauge theories regularized by higher covariant derivatives produced by the supergraphs containing loops of the Faddeev--Popov ghosts. This is done using a recently proposed algorithm, which essentially simplifies such multiloop calculations. The result is presented in the form of an integral of double total derivatives in the momentum space. The considered contribution to the $\beta$-function is compared with the two-loop anomalous dimension of the Faddeev--Popov ghosts. This allows verifying the validity of the NSVZ equation written as a relation between the $\beta$-function and the anomalous dimensions of the quantum superfields. It is demonstrated that in the considered approximation the NSVZ equation is satisfied for the renormalization group functions defined in terms of the bare couplings. The necessity of the nonlinear renormalization for the quantum gauge superfield is also confirmed.Comment: 20 pages, 4 figures, minor corrections, the final version to appear in Eur.Phys.J.

Signal recognition and background suppression by matched filters and neural networks for Tunka-Rex

The Tunka Radio Extension (Tunka-Rex) is a digital antenna array, which measures the radio emission of the cosmic-ray air-showers in the frequency band of 30-80 MHz. Tunka-Rex is co-located with TAIGA experiment in Siberia and consists of 63 antennas, 57 of them are in a densely instrumented area of about 1 km\textsuperscript{2}. In the present work we discuss the improvements of the signal reconstruction applied for the Tunka-Rex. At the first stage we implemented matched filtering using averaged signals as template. The simulation study has shown that matched filtering allows one to decrease the threshold of signal detection and increase its purity. However, the maximum performance of matched filtering is achievable only in case of white noise, while in reality the noise is not fully random due to different reasons. To recognize hidden features of the noise and treat them, we decided to use convolutional neural network with autoencoder architecture. Taking the recorded trace as an input, the autoencoder returns denoised trace, i.e. removes all signal-unrelated amplitudes. We present the comparison between standard method of signal reconstruction, matched filtering and autoencoder, and discuss the prospects of application of neural networks for lowering the threshold of digital antenna arrays for cosmic-ray detection.Comment: ARENA2018 proceeding

The Tunka Experiment: Towards a 1-km^2 Cherenkov EAS Array in the Tunka Valley

The project of an EAS Cherenkov array in the Tunka valley/Siberia with an area of about 1 km^2 is presented. The new array will have a ten times bigger area than the existing Tunka-25 array and will permit a detailed study of the cosmic ray energy spectrum and the mass composition in the energy range from 10^15 to 10^18 eV.Comment: 3 pages, 2 figures, to be published in IJMP

Current Status and New Challenges of The Tunka Radio Extension

The Tunka Radio Extension (Tunka-Rex) is an antenna array spread over an area of about 1~km$^2$. The array is placed at the Tunka Advanced Instrument for cosmic rays and Gamma Astronomy (TAIGA) and detects the radio emission of air showers in the band of 30 to 80~MHz. During the last years it was shown that a sparse array such as Tunka-Rex is capable of reconstructing the parameters of the primary particle as accurate as the modern instruments. Based on these results we continue developing our data analysis. Our next goal is the reconstruction of cosmic-ray energy spectrum observed only by a radio instrument. Taking a step towards it, we develop a model of aperture of our instrument and test it against hybrid TAIGA observations and Monte-Carlo simulations. In the present work we give an overview of the current status and results for the last five years of operation of Tunka-Rex and discuss prospects of the cosmic-ray energy estimation with sparse radio arrays.Comment: Proceedings of E+CRS 201

The first experience of low-invasive correction of Pectus Carinatum at children by Abramson procedur

Purpose: justification of relevance of use of a low-invasive method of correction across Abramson and improvement of treatment of pectus carinatum (PC) at children. Materials and methods. The result of treatment of 7 boys aged from 12 up to 17 years operated from 2012 to 2017 concerning PC in MRRCI was analyzed. 4 of them were operated in the open way on Ravich. A lot of sequels during and after operation led to refusal of open methods of correction of PC. In the period from 2015 to 2017 three children were operated by Abramson’s method. Dynamometer researches proved the efficiency of Abramson’s method. The multispiral computer tomography with 3D reconstruction was carried out and allowed to avoid possible intraoperative complications. During the operation were used epidural and general anesthesia. Allocation of ribs in places of bracing of stabilizers to a periosteum without injury of a pleura allowed to reach the best stability and reliability of fixatives, reduce a pain syndrome and avoid a possible injury of intrathoracic organs. Epidural anesthesia in combination with analgetics intramusculary provided optimum anesthesia during the postoperative period. This method leads to faster recovery after operation, 5 days vs 10 days. Results: the catamnesis collected from 1 month till 2 years is positive. At 1 patient the early postoperative period was complicated by the intense pheumothorax caused by a rupture of a bulla of an apex of the right lung. The thoracoscopic atypical resection of the violent changed site of a lung is executed. Inputs. Using of Abramson’s method allowed to reduce quantity possible intra-and postoperative complications, achieve amazing cosmetic result and reduce terms of hospitalization by 2,5 times