119233536
Using the cathode surface of straw tube for measuring the track coordinates along the wire
The coordinate detectors based on straw tubes provide a high accuracy of the radial coordinate measurement using the drift time and a small amount of matter in the way of the measured particles. However, the measurement of the coordinate along the wire constitutes a problem. This paper proposes a method for measuring the hit coordinate along the wire with an accuracy better than 1 mm in a straw tube detector using the signals from the cathodes of the detector.
119270809
Detector with a profile-based cathode and the two-coordinate pad-strip readout system
A detector with a profile-based cathode and a two-coordinate cathode readout system has been experimentally investigated. Cathode pads located in each profile along the anode wire are diagonally interconnected, thus forming strips that cross the detector at some angle with respect to the anode wire. Owing to the availability of the two cathode coordinates and the coordinate associated with the anode wire, it is possible to solve the problem of identifying high-multiplicity events in a single detector.
122046947
ARES — a spectrometer for the investigation of rare particle decays and rare nuclear processes
Abstract A magnetic spectrometer intended for a wide range of investigations of rare particle and nuclear processes is described. The spectrometer consists of cylindrical proportional chambers (∼ 15000 signal wires) with gas supply and gas leakage systems, cylindrical scintillation hodoscopes, a magnet, electronics with power supplies, and a data acquisition system. Basic characteristics of the spectrometer are discussed and results of first physics experiments are presented.
107380479
Shock tensiometer for multiwire chambers
This paper describes the operation and circuit of a tensometer based on a new method of determining the frequency of natural oscillations of multiwire chambers filaments by means of shock excitation of oscillations that provide sufficient accuracy under the indicated measurement conditions. The device is suitable for measuring the filament tension of chambers of various designs, is simple to operate, and provides high productivity. The range of tension measurement of 0.5-70 g for gold-plated tungsten filaments 20 microm in diameter and 60 cm long is established with the device.
12254630
Subleading Sudakov logarithms in electroweak processes
Abstract Recent results for the asymptotic behavior of fermion scattering amplitudes in the Sudakov limit are presented including next-to-leading logarithmic corrections. These are used for the analysis of the dominant electroweak corrections to the fermion-antifermion pair production in e+e−annihilation at high energy.
121202255
TWO LOOP CALCULATIONS IN THE LARGE QUARK MASS EXPANSION IN THE FRAMEWORK OF THE QCD SUM RULES METHOD
Abstract The coefficient function (CF) of the operator G 2 = G μv a G aμv in the large quark mass expansion of the correlator of two vector currents is calculated in the two-loop approximation. The obtained results show, in particular, that α s 2 -corrections to this CF are reasonably small and can hardly reduce the disagreement between the values of the corresponding condensate 〈 G 2 〉 0 found in different approaches.
109801893
Development of a data acquisition system for the SPHERE spectrometer
Abstract The 4π-detector SPHERE for studying multiple particle cumulative production is currently under construction at the Laboratory of High Energies, JINR, Dubna. This paper briefly describes the present status and future developments of the data acquisition system for this setup. A multiprocessor system based on VMEbus will be implemented for parallel readout, event-building, and data preprocessing. A workstation will be used for data analysis and experimental control. The investigation has been performed at the Laboratory of High Energies, JINR.
67213603
A supercomputer for parallel data analysis
119487843
Magic identities for conformal four-point integrals
We propose an iterative procedure for constructing classes of off-shell four-point conformal integrals which are identical. The proof of the identity is based on the conformal properties of a subintegral common for the whole class. The simplest example are the so-called `triple scalar box' and `tennis court' integrals. In this case we also give an independent proof using the method of Mellin–Barnes representation which can be applied in a similar way for general off-shell Feynman integrals.