45 research outputs found
Instanton propagator and instanton induced processes in scalar model
The propagator in the instanton background in the
scalar model in four dimensions is studied.Leading and sub-leading terms of its
asymptotics for large momenta and its on-shell double residue are calculated
analytically. These results are applied to the analysis of the initial-state
and initial-final-state corrections and the calculation of the next-to-leading
(propagator) correction to the exponent of the cross section of instanton
induced multiparticle scattering processes.Comment: 44 pages, 7 postscript figures, LaTe
Measurement of the neutron electric dipole moment by crystal diffraction
An experiment using a prototype setup to search for the neutron electric
dipole moment by measuring spin-rotation in a non-centrosymmetric crystal
(quartz) was carried out to investigate statistical sensitivity and systematic
effects of the method. It has been demonstrated that the concept of the method
works. The preliminary result of the experiment is ecm. The experiment showed that an accuracy of ecm can be obtained in 100 days data taking, using available
quartz crystals and neutron beams.Comment: 13 pages, 4 figure
Measurement of the neutron electric dipole moment via spin rotation in a non-centrosymmetric crystal
We have measured the neutron electric dipole moment using spin rotation in a
non-centrosymmetric crystal. Our result is d_n = (2.5 +- 6.5(stat) +-
5.5(syst)) 10^{-24} e cm. The dominating contribution to the systematic
uncertainty is statistical in nature and will reduce with improved statistics.
The statistical sensitivity can be increased to 2 10^{-26} e cm in 100 days
data taking with an improved setup. We state technical requirements for a
systematic uncertainty at the same level.Comment: submitted to Phys. Lett.
d dimensional SO(d)-Higgs Models with Instanton and Sphaleron: d=2,3
The Abelian Higgs model and the Georgi-Glashow model in 2 and 3 Euclidean
dimensions respectively, support both finite size instantons and sphalerons.
The instantons are the familiar Nielsen-Oleson vortices and the 't
Hooft-Polyakov monopole solutions respectively. We have constructed the
sphaleron solutions and calculated the Chern-Simons charges N_cs for sphalerons
of both models and have constructed two types of noncontractible loops between
topologically distinct vacuua. In the 3 dimensional model, the sphaleron and
the vacuua have zero magnetic and electric flux while the configurations on the
loops have non vanishing magnetic flux.Comment: 24 pages, 3 figures, LaTe
Matter Outflows from AGN: A Unifying Model
We discuss a self-consistent unified model of the matter outflows from AGNs
based on a theoretical approach and involving data on AGN evolution and
structure. The model includes a unified geometry, two-phase gas dynamics,
radiation transfer, and absorption spectrum calculations in the UV and X-ray
bands. We briefly discuss several questions about the mass sources of the
flows, the covering factors, and the stability of the narrow absorption
details.Comment: 6 figures, accepted for publication in Astrophysics and Space Scienc
Experimental Study of Features of Thin-Walled Pipes Sizing in the Line of a Pipe Rolling Plant with an Automatic Mill
The aim of the study is to establish the actual level of working loads on the roll drive line of the sizing mill installed as part of the PRP-220 with an automatic mill, when switching to the production of steel pipes from increased strength group. The study is based on a complex experimental and theoretical analysis. After the processing of the results of experimental studies a comparison of the most loaded sizing route for a thin-walled pipe with a diameter of 244.5 mm and a wall thickness of 8.9 mm (D/S = 27.5) made of steel of strength group “D” was made with the route for a pipe with a diameter of 177.8 mm and a wall thickness of 9.2 mm (D/S = 19.3) from steel of strength group “E”. Graphs of the observed processes are presented, as well as calculated predictive values of sizing of thin-walled pipes for steel of strength group “E”, obtained on the basis of an experimental-theoretical analysis of the growth of flow stress. Recommendations have been given for improving the equipment of the PRP-220 sizing mill for the production of pipes with increased diameters from steels of increased strength groups
Zoogeographical analysis of the hoverfly fauna (Diptera, Syrphidae) of the northwestern Caucasus
The first results of mass U-Pb isotope dating (LA-ICP-MS) for detrital zircons from the Asha Group, South Urals: Paleogeography and paleotectonics
[No abstract available