62324462
The Data Acquisition of the Sphere 4$\pi$-Detector
64925563
Universal CAMAC Branch Driver
121235164
Architecture of data-acquisition systems for high-energy physics experiments
In this review we discuss the evolution of the basic principles of the architecture of data-acquisition systems for experimental setups used in high-energy physics and relativistic nuclear physics during the last 25 years. The effect of the latest advances in computational techniques and communications, such as microprocessors and open bus system standards, on improving data recording and acquisition is discussed. The evolution of data-acquisition systems is illustrated by examples of developments occurring at the leading physics centers and at the Laboratory of High Energy Physics, JINR, Dubna. The trends in the future development of data-acquisition systems are described for the research programs at the LHCcollider, CERN, and the Relativistic Heavy Ion Collider at Brookhaven National Laboratory.
139621105
SPECTROMETER WITH SEMICONDUCTOR DETECTORS ONLINE WITH HP-2116B COMPUTER
15373665
Analytical results for dimensionally regularized massless on-shell double boxes with arbitrary indices and numerators
Abstract We present an algorithm for the analytical evaluation of dimensionally regularized massless on-shell double box Feynman diagrams with arbitrary polynomials in numerators and general integer powers of propagators. Recurrence relations following from integration by parts are solved explicitly and any given double box diagram is expressed as a linear combination of two master double boxes and a family of simpler diagrams. The first master double box corresponds to all powers of the propagators equal to one and no numerators, and the second master double box differs from the first one by the second power of the middle propagator. By use of differential relations, the second master double box is expressed through the first one up to a similar linear combination of simpler double boxes so that the analytical evaluation of the first master double box provides explicit analytical results, in terms of polylogarithms Li a −t/s , up to a=4, and generalized polylogarithms Sa,b(−t/s), with a=1,2 and b=2, dependent on the Mandelstam variables s and t, for an arbitrary diagram under consideration.
16910552
Threshold behavior of Feynman diagrams: the master two-loop propagator
Abstract An asymptotic expansion of the two-loop two-point “master” diagram with two masses m and M , on the mass shell Q 2 = M 2 , is presented. The treatment of the non-analytical terms arising in the expansion around the branching point is discussed. Some details of the calculation of a new class of two-loop integrals are given.
2122861
Decoupling of heavy quarks in HQET
Decoupling of c-quark loops in b-quark HQET is considered. The decoupling coefficients for the HQET heavy-quark field and the heavy–light quark current are calculated with the three-loop accuracy. The last result can be used to improve the accuracy of extracting fB from HQET lattice simulations (without c-quark loops). The decoupling coefficient for the flavour-nonsinglet QCD current with n antisymmetrized γ-matrices is also obtained at three loops; the result for the tensor current (n = 2) is new.
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.
122131877
Calculation of infrared-divergent Feynman diagrams with zero mass threshold
Abstract. Two-loop vertex Feynman diagrams with infrared and collinear divergences are investigated by two independent methods. On the one hand, a method of calculating Feynman diagrams from their small momentum expansion [1] extended to diagrams with zero mass thresholds [2] is applied. On the other hand, a numerical method based on a two-fold integral representation is used [3], [4]. The application of the latter method is possible by using lightcone coordinates in the parallel space. The numerical data obtained with the two methods are in impressive agreement.