2,075 research outputs found
The Adler -function for SQCD regularized by higher covariant derivatives in the three-loop approximation
We calculate the Adler -function for SQCD in the three-loop
approximation using the higher covariant derivative regularization and the
NSVZ-like subtraction scheme. The recently formulated all-order relation
between the Adler function and the anomalous dimension of the matter
superfields defined in terms of the bare coupling constant is first considered
and generalized to the case of an arbitrary representation for the chiral
matter superfields. The correctness of this all-order relation is explicitly
verified at the three-loop level. The special renormalization scheme in which
this all-order relation remains valid for the -function and the anomalous
dimension defined in terms of the renormalized coupling constant is constructed
in the case of using the higher derivative regularization. The analytic
expression for the Adler function for SQCD is found in this scheme
to the order . The problem of scheme-dependence of the
-function and the NSVZ-like equation is briefly discussed.Comment: 25 pages, 2 figures; the version accepted for publication in Nuclear
Physics
Diffraction radiation from a screen of finite conductivity
An exact solution has been found for the problem of diffraction radiation
appearing when a charged particle moves perpendicularly to a thin finite screen
having arbitrary conductivity and frequency dispersion. Expressions describing
the Diffraction and Cherenkov emission mechanisms have been obtained for the
spectral-angular forward and backward radiation densities.Comment: 6 pages, 4 figure
Spectral analysis of granular material reaction to long-term weak dynamic effect
The paper demonstrates the similarity of alternating reaction of rocks to explosions to the response of a granular material to repetitive (up to 330 thousands) light shocks (3.85 -10{-3} J, frequency 1.33 Hz). The cause of both reactions is multiple forms of equilibrium of geomaterials. It has been stated that pressure of the sensor in a granular material subject to long-term weak effects doesn't relax to the hydrostatic one, but oscillates about it with the amplitude about its value. The spectral density of this process obeys the power dependence on the frequency; the exponent is typical for black noise
- β¦