120159616
Evaluation of three-loop feynman diagrams by four-dimensional integration by parts and differential renormalization
Four-dimensional integration by parts, combined with differential renormalization, is applied to evaluate three-loop Feynman diagrams.
16218113
Analytical result for dimensionally regularized massless master double box with one leg off shell
Abstract The dimensionally regularized massless double box Feynman diagram with powers of propagators equal to one, one leg off the mass shell, i.e. with nonzero q 2 = p 1 2 , and three legs on shell, p i 2 =0, i=2,3,4 , is analytically calculated for general values of q 2 and the Mandelstam variables s and  t . An explicit result is expressed through (generalized) polylogarithms, up to the fourth order, dependent on rational combinations of q 2 , s and  t , and a one-dimensional integral with a simple integrand consisting of logarithms and dilogarithms.
122087913
Singularities of feynman amplitudes in the momentum space
119544460
Two-Loop Electroweak Logarithms
We present the complete analytical result for the two-loop logarithmically enhanced contributions to the high energy asymptotic behavior of the vector form factor and the four-fermion cross section in a spontaneously broken SU(2) gauge model. On the basis of this result we derive the dominant two-loop electroweak corrections to the neutral current four-fermion processes at high energies.
122058141
R* operation in the minimal subtraction scheme
This paper develops the formalism of the R* operation; it generalizes the R operation and eliminates both ultraviolet and infrared divergences. By explicit formulation of the concept of an infrared counterterm it is shown that the calculation of an arbitrary (R+1) loop ultraviolet or infrared counterterm in the minimal substraction scheme can be reduced to the finding of the divergent and finite parts of certain massless Feynman integrals that depend only on a single external momentum with number loops not exceeding R.
15966773
Fermionic contributions to the three-loop static potential
Abstract We consider the three-loop corrections to the static potential which are induced by a closed fermion loop. For the reduction of the occurring integrals a combination of the Grobner and Laporta algorithm has been used and the evaluation of the master integrals has been performed with the help of the Mellin–Barnes technique. The fermionic three-loop corrections amount to 2% of the tree-level result for top quarks, 8% for bottom quarks and 27% for the charm quark system.
121228290
Intellectual system for power supply and control of magnetic component groups of particle accelerators from several MW-power sources
It is necessary for the power-consuming magnetic components of channels for beam transport in accelerators of charged particles be supplied with direct current. An individual power source is typically applied for each group of identical components. A variant of the simultaneous supply of several groups of magnets from a single medium-power source using auxiliary current shunts of different types is given by the example of a LEPTA positron storage ring. One version of using this technology with MW-power sources for a phasotron accelerator is developed. The efficiency of putting this technology into practice with the application of start-stop regimes for the phasotron is estimated.
117312301
The experimental verification of the hypothesis of the existence of the static electromagnetic field
139621105
SPECTROMETER WITH SEMICONDUCTOR DETECTORS ONLINE WITH HP-2116B COMPUTER
26253853
Project of the Dubna Electron Synchrotron
The project "Dubna Electron Synchrotron" (DELSY) is aimed to construct a synchrotron radiation source of the 3d generation at the Joint Institute for Nuclear Research. The DELSY synchrotron radiation source will be constructed on the base of the accelerator facility of the Institute for Nuclear Physics and High Energy Physics (NIKHEF), Amsterdam, the Netherlands. This accelerator facility consists of a linear electron accelerator MEA (Medium Energy Accelerator) for the electron energy of 700 MeV and the electron storage ring AmPS (Amsterdam Pulse Stretcher) for the maximum electron energy of 900 MeV at the circulating beam current of 200 mA. The DELSY storage ring is supposed to be constructed with the use of the "Amsterdam Pulse Stretcher" (AmPS) [1] storage ring the focusing system of which will be essentially modified: the ring circumference will be approximately 1.5 times smaller, the electron energy will be increased up to 1.2 GeV and the focusing strength will be enhanced. These measures will allow obtaining the beam emittance at least ten times smaller which subsequently increases the synchrotron radiation brilliance by several orders of magnitude. The rigging of the DELSY ring with the insertion devices — the superconducting wiggler with the magnetic field of 10 T and the so-called "vacuum hybrid miniundulator" is the principle feature of the new synchrotron radiation source. Both devices developed by Budker INP, Novosibirsk, will allow to enrich the DELSY characteristics as the synchrotron radiation source expanding its radiation spectrum in the region of the hard X-rays and increasing its brilliance up to 3 ⋅10 18
62324462
The Data Acquisition of the Sphere 4$\pi$-Detector