Estimates for parameters and characteristics of the confining SU(3)-gluonic field in an η′\eta^\prime-meson

The confinement mechanism proposed earlier by the author is applied to estimate the possible parameters of the confining SU(3)-gluonic field in an $\eta^\prime$-meson. For this aim the electric form factor of an $\eta^\prime$-meson is nonperturbatively computed in an explicit analytic form. The estimates obtained are also consistent with the width of the electromagnetic decay $\eta^\prime\to2\gamma$. The corresponding estimates of the gluon concentrations, electric and magnetic colour field strengths are also adduced for the mentioned field at the scales of the meson under consideration.Comment: 20 pages, LaTe

Symbols of One-Loop Integrals From Mixed Tate Motives

We use a result on mixed Tate motives due to Goncharov (arXiv:alg-geom/9601021) to show that the symbol of an arbitrary one-loop 2m-gon integral in 2m dimensions may be read off directly from its Feynman parameterization. The algorithm proceeds via recursion in m seeded by the well-known box integrals in four dimensions. As a simple application of this method we write down the symbol of a three-mass hexagon integral in six dimensions.Comment: 13 pages, v2: minor typos correcte

Asymptotic normalization coefficients for mirror virtual nucleon decays in a microscopic cluster model

It has been suggested recently (Phys. Rev. Lett. 91, 232501 (2003)) that charge symmetry of nucleon-nucleon interactions relates the Asymptotic Normalization Coefficients (ANCs) of proton and neutron virtual decays of mirror nuclei. This relation is given by a simple analytical formula which involves proton and neutron separation energies, charges of residual nuclei and the range of their strong interaction with the last nucleon. Relation between mirror ANCs, if understood properly, can be used to predict astrophysically relevant direct proton capture cross sections using neutron ANCs measured with stable beams. In this work, we calculate one-nucleon ANCs for several light mirror pairs, using microscopic two-, three- and four-cluster models, and compare the ratio of mirror ANCs to the predictions of the simple analytic formula. We also investigate mirror symmetry between other characteristics of mirror one-nucleon overlap integrals, namely, spectroscopic factors and single-particle ANCs.Comment: 12 pages, submitted to Phys. Rev.

Damages Identification in the Cantilever-based on the Parameters of the Natural Oscillations

An approach to parametric identification of damages such as cracks in the rod cantilever construction is described. The identification method is based on analysis of shapes of the natural oscillations. The analytic modelling is performed in the Maple software on the base of the Euler-Bernoulli hypothesis. Crack is modelled by an elastic bending element. Transverse oscillations of the rod are considered. We take into account first four eigen modes of the oscillations. Parameters of amplitude, curvature and angle of bends of the waveforms are analysed. It was established that damage location is revealed by ‘kink’ on corresponding curves of the waveforms. The parameters of oscillation shapes are sensitive to the crack parameters in different degree. The novelty of the approach consists in that the identification procedure is divided into two stages: (a) it is determined the crack location, and (b) it is determined the crack size. Based on analytical modelling, an example of determination of dependence of the crack parameters on its size in the cantilever rod is presented. Study of features of the waveforms during identification of the fracture parameters shows that the features found in the form of ‘kinks’ and local extreme a of the angle between the tangent and curvature of waveforms for different modes of bending oscillations, define the crack location in cantilever. They can serve as one of diagnostic signs of crack identification and allow us to determine its location. 

Laser synthesis of optical media with silver nanoparticles by nanosecond pulses at air.

The present work is dedicated to further development of the laser synthesis method for metal nanoparticles formation at air conditions. On the base of complex investigation of processes taking place during laser erosion of metals by intensive nanosecond pulses the method of silver nanoparticles fluxes is proposed. By the implantation of silver nanoparticles into liquid media (water or solutions of a polymeric base) the transarent media with silver nanoparticles can be obtained (particularly water colloids and modified polimer films). For the aims of investigation of formed polymeric films the complex diagnostics method is used Key words: laser erosion of metals, silver nanoparticles, transmission electron microscopy, absorption spectroscopy, surface plasmon resonance