Radiative decay of $b$-quark in a non-Abelian chromomagnetic field
Radiative decay of $b$-quark in a non-Abelian chromomagnetic field
A.E. Grigoruk, V.Ch. Zhukovskii
The spectrum and the width of the $b \to s+\gamma $ decay in an external non-Abelian chromomagnetic field simulating the vacuum gluon condensate have been evaluated. The obtained result is consistent with similar nonperturbative corrections calculated earlier by other methods. But the exact functional dependence of the probability of decay on the condensate field intensity disagrees with predictions of other authors who used unfounded approximations. It is shown that the effect of gluon condensate reduces to an increase in the quark mass and to the interaction of the chromatic magnetic moment with the chromomagnetic field.
Show AbstractRay diffusion in anisotropic media
Ray diffusion in anisotropic media
V.D. Gusev, O.K. Vlasova
Dynamic equations have been derived which describe ray diffusion in the weak-fluctuation approximation for any anisotropic medium. A technique for going from ray equations in an anisotropic medium with random inhomogeneities of the refraction index to Einstein-Fokker equations has been suggested. As an example, the problem of light scattering in a uniaxial crystal is solved. The formula derived for the transition probability of the beam state indicates anisotropic scattering even for an isotropic correlation function of scattering inhomogeneities.
Show AbstractIntermittence of structural states of laser beams on near-the-ground paths
Intermittence of structural states of laser beams on near-the-ground paths
T.I. Arsenyan, L.S. Kornienko, P.V. Korolenko, E.A. Kulyagina, G.V. Petrova, N.N. Fedotov
This paper is concerned with the phenomenon of the intermittence of structural states of laser beams-quasiperiodic discontinuous transitions between two structural states of the beam (a dislocationless and a stochastic state). The authors have studied the conditions of appearance and the specific features of manifestation of structural intermittence on near-the-ground slant and horizontal paths. The relationship between the optical effects studied and the changes of the turbulent properties of the atmosphere are discussed.
Show AbstractExcess noise in suspensions of torsion pendulums
Excess noise in suspensions of torsion pendulums
A.Yu. Ageev, V.P. Mitrofanov
The equilibrium angular orientation of a torsion pendulum suspended by a thin tungsten wire changes with time. Examining the statistics of such changes over the period of oscillations showed that for low stresses in the wire (less than 60-70% of the breaking stress), the distribution of these values is close to the Gaussian distribution. For high stresses, this distribution differs from a Gaussian one by the presence of rare comparatively large jumps of the rotation angle. They can be considered as a manifestation of strain jumps in solids caused by the dislocation motion. In mechanical systems, strain jumps cause an excess noise, which can make a substantial contribution to fluctuations in the arrangement of test masses of laser gravitational antennas.
Show AbstractPhase stability in the Ginzburg-Devonshire model
Phase stability in the Ginzburg-Devonshire model
G.V. Belokopytov
The thermodynamic potential in the form traditional for the theory of ferroelectric phase transitions in barium titanate has been considered. It has been proved that the potential admits the existence of a monoclinic phase. The physical reasons for its absence in $BaTiO_3$ have been found out. The conditions under which the polarization jump on the equilibrium surface of polar phases in phase transitions is negligibly small have been determined.
Show AbstractManifestation of structural features in the cation sublattice of the 2212-type single crystals in Raman scattering
Manifestation of structural features in the cation sublattice of the 2212-type single crystals in Raman scattering
L.I. Leonyuk$^1$, G.-Yu. Babonas$^2$
A series of 2212-type single crystals grown by the method of cooling a nonstoichiometric melt has been examined. For specimens with controlled chemical and phase compositions, the dependence of the fine structure of their Raman spectra on the alloying effects and the presence of isostructural phases has been determined. The results can be used for optical diagnostics.
Show AbstractWater basin heat losses under the conditions of free convection
Water basin heat losses under the conditions of free convection
Ya.L. Aleksandrov, E.P. Anisimova, S.N. Dikarev, A.A. Speranskaya, O.A. Speranskaya
An integral numerical model is discussed which allows one to determine the density of the heat flux from water to air under the conditions of free convection in a nonaerated water mass. The primary external model parameters include the water and air temperatures and the air humidity and do not include the temperature of the underlying water surface. The calculated heat losses from a basin are compared with experimental data.
Show AbstractCorrelation between the Earth's global magnetic and gravity fields
Correlation between the Earth's global magnetic and gravity fields
N.A. Chuikova, N.V. Alakhverdova
The correlation between the anomalies of the gravity ( G) and magnetic (M) fields which have common sources of uniform magnetization is studied. Formulas for the G- and M-potentials of such sources are obtained. The following cases are analyzed theoretically and calculated for actual models of the Earth's G- and M-fields: (1) the G- and M-potentials are created by a uniformly magnetized body with different directions of magnetization; (2) the G- and M-potentials are created by sources with different orientations of their magnetic moments, located on a spherical surface.
Show AbstractMotion of poles of the Earth's principal axes of inertia due to Earth's rotational deformation
Motion of poles of the Earth's principal axes of inertia due to Earth's rotational deformation
Yu.V. Barkin
The variations in the coefficients of the second harmonic of the geopotential that are caused by periodic motions of the pole and by the irregularities of the diurnal rotation of the Earth were determined for an Earth model with an elastic mantle. Periodic perturbations in the motion of the poles of the Earth's polar and equatorial axes of inertia were found which are caused by perturbations of the components of the Earth's angular velocity.
Show AbstractEffect of gyroscope plane inclination on the accuracy of determination of the Earth's rotation parameters
Effect of gyroscope plane inclination on the accuracy of determination of the Earth's rotation parameters
V.E. Zharov, S.N. Markova, M.V. Sazhin
A laser gyroscope has been developed in the Sternberg State Institute of Astronomy for the determination of the Earth's rotation parameters. This work is concerned with the effect of the relative inclination of mirrors on the accuracy of determination of these parameters.
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