TRTViewer: the ATLAS TRT detector monitoring and diagnostics tool

The transition radiation tracker (TRT) is the outermost of the three sub-systems of the ATLAS inner detector at the Large Hadron Collider (LHC) at CERN. It is designed to combine the drift tube tracker with the transition radiation detector, providing an important contribution to the charged particles precise momentum measurement and particle (mainly electron) identification. The TRT consists of a barrel section at small pseudorapidity (eta) and two separate end-cap partitions at large eta. The detector performance and its operational conditions were permanently monitored during all commissioning and data-taking stages using various software tools, one of which - TRTViewer - is described in the present paper. The TRTViewer is the dedicated program for monitoring the TRT raw data quality and detector performance at different hardware levels: individual straws, readout chips and electronic boards. The data analysis results can be presented on the event-by-event basis or in the form of color maps representing the operation parameters (efficiencies, timing, occupancy, etc.) according to the real geometrical position of the detector hardware elements. The paper describes the TRTViewer software package as the event displaying tool, raw data processor and histogram and operation parameters presenter, which works with the different sources of input information: raw data files, online monitoring histograms, offline analysis histograms and TRT DAQ Configuration database. The package proved to be one of the main instruments for the fast and effective TRT diagnostics during debugging and operation periods.Comment: 7 pages, 2 figures. Proc. of the 4th Workshop on Advanced Transition Radiation Detectors for Accelerator and Space Applications, Bari, Italy, Sept. 14-16, 2011. Submitted to Nucl. Instr. Meth.

New formulas for Maslov's canonical operator in a neighborhood of focal points and caustics in 2D semiclassical asymptotics

We suggest a new representation of Maslov’s canonical operator in a neighborhood of caustics using a special class of coordinate systems (eikonal coordinates) on Lagrangian manifolds. We present the results in the two-dimensional case and illustrate them with examples

Structural and superconducting transition in selenium under high pressures

First-principles calculations are performed for electronic structures of two high pressure phases of solid selenium, $\beta$-Po and bcc. Our calculation reproduces well the pressure-induced phase transition from $\beta$-Po to bcc observed in selenium. The calculated transition pressure is 30 GPa lower than the observed one, but the calculated pressure dependence of the lattice parameters agrees fairly well with the observations in a wide range of pressure. We estimate the superconducting transition temperature $T_{\rm c}$ of both the $\beta$-Po and the bcc phases by calculating the phonon dispersion and the electron-phonon interaction on the basis of density-functional perturbation theory. The calculated $T_{\rm c}$ shows a characteristic pressure dependence, i.e. it is rather pressure independent in the $\beta$-Po phase, shows a discontinuous jump at the transition from $\beta$-Po to bcc, and then decreases rapidly with increasing pressure in the bcc phase.Comment: 8 pages, 11 figure

On integrability of one third-order nonlinear evolution equation

We study one third-order nonlinear evolution equation, recently introduced by Chou and Qu in a problem of plane curve motions, and find its transformation to the modified Korteweg - de Vries equation, its zero-curvature representation with an essential parameter, and its second-order recursion operator.Comment: 10 page

Coupled KdV equations of Hirota-Satsuma type

It is shown that the system of two coupled Korteweg-de Vries equations passes the Painlev\'e test for integrability in nine distinct cases of its coefficients. The integrability of eight cases is verified by direct construction of Lax pairs, whereas for one case it remains unknown

A Non-Algebraic Patchwork

Itenberg and Shustin's pseudoholomorphic curve patchworking is in principle more flexible than Viro's original algebraic one. It was natural to wonder if the former method allows one to construct non-algebraic objects. In this paper we construct the first examples of patchworked real pseudoholomorphic curves in $\Sigma_n$ whose position with respect to the pencil of lines cannot be realised by any homologous real algebraic curve.Comment: 6 pages, 1 figur

Percolative nature of the transition from 60 K to 90 K phase in YBa2Cu3O6+d

We have measured the heat capacity of YBa2Cu3O6+d for 0.7<d<0.8 between 1.8 and 300K. It was found that doping dependences of specific heat jump and temperature of heat capacity jump contradict to the assumption of spatially homogeneous electronic density. The results suggest that the transition from 60K to 90K phase has a percolative nature and the structure of underdoped 60K phase can be considered as array of superconducting nanoclusters embedded in the insulating matrix.Comment: Submitted to proceedings of M2S-IX 2009, Tokyo (Physica C

Semiclassical transition probabilities for interacting oscillators

Semiclassical transition probabilities characterize transfer of energy between "hard" and "soft" modes in various physical systems. We establish the boundary problem for singular euclidean solutions used to calculate such probabilities. Solutions are found numerically for a system of two interacting quartic oscillators. In the double-well case, we find numerical evidence that certain regular {\em minkowskian} trajectories have approximate stopping points or, equivalently, are approximately periodic. This property leads to estimates of tunneling excitation probabilities in that system and suggests that similar estimates may be possible in other systems with tunneling.Comment: 19 pages, LATEX, PURD-TH-94-03 (adds estimates of accuracy of numerical calculations