Strong short-range magnetic order in a frustrated FCC lattice and its possible role in the iron structural transformation

We investigate magnetic properties of a frustrated Heisenberg antiferromagnet with a face-centered cubic (FCC) lattice and exchange interactions between the nearest- and next-nearest neighbours, J1 and J2. In a collinear phase with the wave vector Q = (pi,pi,pi) the equations of the self-consistent spin-wave theory for the sublattice magnetization and the average short range order parameter are obtained and numerically solved. The dependence of the Neel temperature T_N on the ratio J2/J1 is obtained. It is shown, that at strong enough frustration there is a wide temperature region above T_N with strong short range magnetic order. Application of this result to description of structural phase transition between alpha and gamma-phase of Fe is considered

The p(d,p)d and p(d,p)pn reactions as a tool for the study of the short range internal structure of the deuteron

In recent time the deuteron structure at short distances is often treated from the point of view nonnucleonic degrees of freedom. In this paper the measurements of T-odd polarization observables using tensor polarized deuteron beam and polarized proton target or proton polarimeter are proposed to search the quark configurations inside the deuteron.Comment: 12 pages, 8 Postscript figures, submitted in Phys.Atom.Nuc

Universal Berezinskii-Kosterlitz-Thouless dynamic scaling in the intermediate time range in frustrated Heisenberg antiferromagnets on a triangular lattice

We investigate nonequilibrium properties of the frustrated Heisenberg antiferromagnets on the triangular lattice. Nonequilibrium critical relaxation of frustrated Heisenberg antiferromagnets shows a dynamic transition (or, at least, sharp crossover) near the temperature Tu=0.282J of the equilibrium Z2-vortex unbinding. We show that starting from the high-temperature initial state, due to the presence of Z2 vortices in the system being considered, in a broad temperature range T<Tu the dynamic properties in the intermediate time range are similar to those of the two-dimensional XY model below the Berezinskii-Kosterlitz-Thouless transition. The interaction of Z2 vortices with spin-wave degrees of freedom does not emerge until rather long times. © 2017 American Physical Society

Evaluation of the influence of combinations of drugs for general anesthesia on change of activity of stress-limiting and stress-realizing links on the clinical model of acute stress damage

When a person is in a state of anesthesia - sedation, the realization of the stress reaction is carried out through the mesocortical - limbic system, while performing intensive therapy outside sedation - through the amygdala and the hippocampus. In this regard, the response of the stress system under anesthesia and outside it will be different and, consequently, the evaluation of reactions during anesthesia is extremely interesting and necessary for targeted (individual) choice of combinations of drugs for anesthesia, depending on their effect on the links of the stress system. The more interesting is the response of the stress system in the conditions of the existing pathology, which in itself is accompanied by a stressful respons

Zero temperature phases of the frustrated J1-J2 antiferromagnetic spin-1/2 Heisenberg model on a simple cubic lattice

At zero temperature magnetic phases of the quantum spin-1/2 Heisenberg antiferromagnet on a simple cubic lattice with competing first and second neighbor exchanges (J1 and J2) is investigated using the non-linear spin wave theory. We find existence of two phases: a two sublattice Neel phase for small J2 (AF), and a collinear antiferromagnetic phase at large J2 (CAF). We obtain the sublattice magnetizations and ground state energies for the two phases and find that there exists a first order phase transition from the AF-phase to the CAF-phase at the critical transition point, pc = 0.28. Our results for the value of pc are in excellent agreement with results from Monte-Carlo simulations and variational spin wave theory. We also show that the quartic 1/S corrections due spin-wave interactions enhance the sublattice magnetization in both the phases which causes the intermediate paramagnetic phase predicted from linear spin wave theory to disappear.Comment: 19 pages, 4 figures, Fig. 1b modified, Appendix B text modifie

Measurement of shower development and its Moli\`ere radius with a four-plane LumiCal test set-up

A prototype of a luminometer, designed for a future e+e- collider detector, and consisting at present of a four-plane module, was tested in the CERN PS accelerator T9 beam. The objective of this beam test was to demonstrate a multi-plane tungsten/silicon operation, to study the development of the electromagnetic shower and to compare it with MC simulations. The Moli\`ere radius has been determined to be 24.0 +/- 0.6 (stat.) +/- 1.5 (syst.) mm using a parametrization of the shower shape. Very good agreement was found between data and a detailed Geant4 simulation.Comment: Paper published in Eur. Phys. J., includes 25 figures and 3 Table

The hyperfine transition in light muonic atoms of odd Z

The hyperfine (hf) transition rates for muonic atoms have been re-measured for select light nuclei, using neutron detectors to evaluate the time dependence of muon capture. For $^{19}$F $\Lambda$$_{h}$ = 5.6 (2) $\mu$s$^{-1}$ for the hf transition rate, a value which is considerably more accurate than previous measurements. Results are also reported for Na, Al, P, Cl, and K; that result for P is the first positive identification.Comment: 12 pages including 5 tables and 4 figures, RevTex, submitted to Phys. Rev.

AC GENERATOR FOR FERROMAGNETIC LIQUID HEATING INVESTIGATION

Ferromagnetic liquids are used in medicine for investigation of hyperthermia research. At present, a number of studies of processes simulating hyperthermia in samples based on ferromagnetic liquids and ferrogels have been carried out at the IEP of the UrB RAS jointly with UrFU. The dependence of the amount of heat in a ferromagnetic liquid on the frequency and on the amplitude of an alternating magnetic field at different concentrations of magnetite nanoparticles is considered

ECFA Detector R&D Panel, Review Report

Two special calorimeters are foreseen for the instrumentation of the very forward region of an ILC or CLIC detector; a luminometer (LumiCal) designed to measure the rate of low angle Bhabha scattering events with a precision better than 10$^{-3}$ at the ILC and 10$^{-2}$ at CLIC, and a low polar-angle calorimeter (BeamCal). The latter will be hit by a large amount of beamstrahlung remnants. The intensity and the spatial shape of these depositions will provide a fast luminosity estimate, as well as determination of beam parameters. The sensors of this calorimeter must be radiation-hard. Both devices will improve the e.m. hermeticity of the detector in the search for new particles. Finely segmented and very compact electromagnetic calorimeters will match these requirements. Due to the high occupancy, fast front-end electronics will be needed. Monte Carlo studies were performed to investigate the impact of beam-beam interactions and physics background processes on the luminosity measurement, and of beamstrahlung on the performance of BeamCal, as well as to optimise the design of both calorimeters. Dedicated sensors, front-end and ADC ASICs have been designed for the ILC and prototypes are available. Prototypes of sensor planes fully assembled with readout electronics have been studied in electron beams.Comment: 61 pages, 51 figure