Uzhhorod National University

About: Uzhhorod National University is a education organization based out in Uzhhorod, Ukraine. It is known for research contribution in the topics: Raman spectroscopy & Laser. The organization has 1089 authors who have published 1056 publications receiving 5187 citations. The organization is also known as: State Higher Education Establishment "Uzhhorod National University" & Uzhhorod State University.

Shape of proton and the pion cloud

Abstract: Proton-proton differential and total cross sections provide information on the energy dependence of proton shape and size. We show that the deviation from exponential behavior of the diffraction cone observed near t = -0.1 GeV2 the so-called break) both at the ISR and the LHC follows from the t-channel two-pion loop contributions, imposed by unitarity. By using a simple Regge pole model, we extrapolate the “break” from the ISR energy region to that of the LHC. This allows us to answer two important questions: 1) To what extent is the “break” observed recently at the LHC a “recurrence” of that seen at the ISR (universality)? 2) What is the relative weight of two-pion effect to the vertex coupling (Regge residue) compared to expanding size (pomeron propagator) in producing the “break”? We find that the effect comes both from the Regge residue (proton-pomeron coupling) and from the Regge propagator. A detailed analysis of their balance, including the correlation between the relevant parameters is presented.

Ab initio and Raman study of medium range ordering in GeSe2 glass

Abstract: High resolution Raman spectra of GeSe 2 glass were measured and fitted using individual Gaussian components The structural origin of the components were interpreted using the results of ab initio density functional theory calculations performed on Ge n Se m nanoclusters (n = 2–6, 12; m = 6–9, 12, 14–16, 30) which represent the local structure of GeSe 2 glass and on some “defect” Ge n Se m clusters that are thought to be related to the inhomogeneity of the structure at the nanoscale The calculated vibrational properties of Ge n Se m nanoclusters and their couplings with the short- and medium-range order structure formations in GeSe 2 glass are analyzed and discussed