Development of aerogel Cherenkov counters at Novosibirsk

Abstract The work on aerogel Cherenkov counters was started in Novosibirsk in 1986. Production of aerogels with refractive indices of 1.006–1.13 and thicknesses of blocks up to 50 mm was developed. The light absorption length at 400 nm is 5–7 m, the scattering length is 4–5 cm. By these parameters, the Novosibirsk aerogel is one of the best in the world. The ASHIPH Cherenkov counters with light collection on wavelength shifters have been developed. The ASHIPH system of the KEDR detector contains 1000 l of aerogel. The π / K separation is 4.5 σ . A project of ASHIPH counters for the SND detector has been developed. Aerogel RICH for LHCb gives a possibility to identify hadrons in the momentum range of 2–10 GeV/c. The Novosibirsk group is developing an aerogel RICH for the endcap for the SuperBaBar project. Calculations performed by a group of physicists from Novosibirsk and DESY-Zeuthen have shown that aerogel radiators enable to achieve time resolution up to 20 fs

Development of aerogel Cherenkov detectors at Novosibirsk

Abstract The development of aerogel Cherenkov counters with the light collection using a wavelength shifter is described. 80 counters of this type are working in the KEDR detector. A project of similar counters for the SND detector based on "heavy" aerogel with n = 1.13 has been developed. Aerogel with a refractive index of 1.006–1.13 and dimensions of blocks up to 200 × 200 × 50 mm 3 is produced by the Novosibirsk group for use in Cherenkov counters of different types. The Novosibirsk group is participating in the development of LHCb RICH as well as a beam diagnostics for a photo-injector test facility at DESY–Zeuthen. Recently we started development of RICH based on focusing aerogel (FARICH) for the endcap of the SuperBaBar. For the first time in the world the focusing aerogel with layers of different refractive indices has been produced

Conversion of self-assembled monolayers into nanocrystalline graphene: Structure and electric transport

Graphene-based materials have been suggested for applications ranging from nanoelectronics to nanobiotechnology. However, the realization of graphene-based technologies will require large quantities of free-standing two-dimensional (2D) carbon materials with tuneable physical and chemical properties. Bottom-up approaches via molecular self-assembly have great potential to fulfil this demand. Here, we report on the fabrication and characterization of graphene made by electron-radiation induced cross-linking of aromatic self-assembled monolayers (SAMs) and their subsequent annealing. In this process, the SAM is converted into a nanocrystalline graphene sheet with well defined thickness and arbitrary dimensions. Electric transport data demonstrate that this transformation is accompanied by an insulator to metal transition that can be utilized to control electrical properties such as conductivity, electron mobility and ambipolar electric field effect of the fabricated graphene sheets. The suggested route opens broad prospects towards the engineering of free-standing 2D carbon materials with tuneable properties on various solid substrates and on holey substrates as suspended membranes.Comment: 30 pages, 5 figure

Isoscalar and isovector kaon form factors from e+e− and τ data

The recent precise measurements of the e+e−→ KS KL and e+e−→ K+K− cross sections and the hadronic spectral function of the τ−→ K−KS ντ decay are used to extract the isoscalar and isovector electromagnetic kaon form factors and their relative phase in a model independent way. The experimental results are compared with a fit based on the vector-meson-dominance model

Isoscalar and isovector kaon form factors from

The recent precise measurements of the e+e−→ KS KL and e+e−→ K+K− cross sections and the hadronic spectral function of the τ−→ K−KS ντ decay are used to extract the isoscalar and isovector electromagnetic kaon form factors and their relative phase in a model independent way. The experimental results are compared with a fit based on the vector-meson-dominance model

Efficacy evaluation of case-specific approach for surgical treatment of incisional ventral hernia

The Aim of research is to improve the results of surgical treatment of incisional ventral hernia by applying a case-specific approach and a new method of plastic repair of anterior abdominal wall. The prospective controlled dynamic study is based on incisional ventral hernia treatment results with the use of meshed endoprostheses among 219 patients. On-lay alloplasty was used in patients younger than 60 years of age, without severe concomitant pathology, with small and medium hernias and anterior abdominal wall defect of up to 10 cm (W1 - W2). The article shows a selection algorithm for anterior abdominal wall plastic repair method. It goes through advantages of the author’s proprietary technique. The article displays frequency and patterns of complications, life quality of the patients after various prosthetic plastic repairs. In the main group, positive treatment results were observed in 65.0%, long-term results of the operation were observed in 88.4%, complications occurred in 13.6%, relapse in 4.5%. «On lay» treatment tactics showed positive results in 59.4%, long-term results of the operation were observed in 74.7%, complications occurred in 40%, relapse in 3.1%. After «sub lay» intervention, excellent results were observed in 40.0% of patients, long-term results of the operation were observed in 81.9%, complications occurred in 12%, and relapse in 1.4%

Hyperon signatures in the PANDA experiment at FAIR

We present a detailed simulation study of the signatures from the sequential decays of the triple-strange pbar p -> Ω+Ω- -> K+ΛbarK- Λ -> K+pbarπ+K-pπ- process in the PANDA central tracking system with focus on hit patterns and precise time measurement. We present a systematic approach for studying physics channels at the detector level and develop input criteria for tracking algorithms and trigger lines. Finally, we study the beam momentum dependence on the reconstruction efficiency for the PANDA detector