Benzindoles

A large amount of structural similarity between 4,5-benzindole and naphthalene and between 6,7-benzindole and indole was detected on a basis of a comparison of the absorption, fluorescence, and phosphorescence spectra of isomeric benzindoles with the spectra of indole and naphthalene. A great analogy between indole and 6,7-benzindole as compared with 4,5-benzindole is also observed during the formation of hydrogen bonds, as indicated by the shift in the absorption band of the NH group in the IR spectra of the investigated compounds in the presence of various proton acceptors.     

Heavy-baryon properties with NLO accuracy in perturbative QCD

We present an analysis of the static properties of heavy baryons at next-to-leading order in the perturbative expansion of QCD. We obtain analytical next-to-leading order three-loop results for the two-point correlators of baryonic currents with one finite-mass quark field for a variety of quantum numbers of the baryonic currents. We consider both the massless limit and the HQET limit of the correlator as special cases of the general finite-mass formula and find agreement with previous results. We present closed-form expressions for the moments of the spectral density. We determine the residues of physical baryon states using sum-rule techniques.     

Heavy quark induced effective action for gauge fields in the SU(N_c)\otimes U(1) model and the low-energy structure of heavy quark current correlators

We calculate the low-energy limit of heavy quark current correlators within an expansion in the inverse heavy quark mass. The induced low-energy currents built from the gluon fields corresponding to the initial heavy quark currents are obtained from an effective action for gauge fields in the one-loop approximation at the leading order of the expansion. Explicit formulae for the low-energy spectra of electromagnetic and tensor heavy quark current correlators are given. Consequences of the appearance of a nonvanishing spectral density below the two-particle threshold for high precision phenomenology of heavy quarks are discussed quantitatively. Received: 21 April 2001 / Revised version: 18 May 2001 / Published online: 29 June 2001     

Contribution of Intermediate Axial Vector States to the [ρ(770), ω(782)] → γ[π, η] Electromagnetic Decays in the Nambu—Jona-Lasinio Model

JETP Letters - The well-known [ρ(770), ω(782)] → γ[π, η] electromagnetic decays have been considered within the Nambu-Jona-Lasinio model taking into account...     

Modeling trajectories and radiation spectra of relativistic particles in crystals. Radiation polarization characteristics

A method is developed for calculation of the polarization characteristics of radiation based on computer tracking of relativistic particle trajectories. The dependence of the Stokes parameter which defines the polarization properties of the radiation upon photon frequency is determined for characteristic trajectories. Formation of full spectra and the degree of linear polarization for averaging over possible trajectories are considered, and results are compared with available experiments.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 63–68, November, 1986.The authors are indebted to S. A. Vorob'ev for his support in the study and evaluation, to M. I. Podgoretskii and A. P. Potyltsyn for their valuable discussion, and to O. V. Boyarko for assistance in formulating the plan of the study.     

Chaos in spacecraft attitude motion in Earth's magnetic field

The rotational motion of a satellite with a magnetic stabilization system is discussed. The motion is described by a nonautonomous differential equation, with the magnetic moment of the satellite as a parameter. The global phase portrait of the problem is investigated in a wide range of magnetic-parameter values, using a numerical realization of the method of Poincare point maps. New periodic solutions of the problem are found, and an analysis is carried out of the evolution of the phase portrait and the bifurcation of periodic solutions with varying magnetic-parameter values. The values of the magnetic parameter that must be avoided in the design of the satellite magnetic stabilization system are discussed. (c) 1999 American Institute of Physics.     

Coherent Type-B e + e- Pair Production by Photons in a Crystal

An overview of theoretical and experimental studies of the coherent type-B e ⁺ e-pair production by photons in aligned crystals performed at Nuclear Physics Institute at Tomsk Polytechnic University is given.     

Sum rule estimate of the subleading non-perturbative contributions to Bs–$\bar{ B}_{s}$ mixing

We use QCD sum rules to compute the matrix elements of the ΔB=2 operators appearing in the heavy-quark expansion of the width difference of the B _s mass eigenstates. The main focus of our analysis is on the subleading operators R ₂ and R ₃, which appear at next-to-leading order in the 1/m _b expansion. The matrix elements of these operators are already essential for precise phenomenology, but their calculation in lattice QCD is lacking and the values given here provide a first estimate of their values. We conclude that the violation of the factorization approximation for these matrix elements due to non-perturbative vacuum condensates is as low as 1–2%.