Angular Distribution of Decay Leptons from e^+e^- \to W^+W^- at Threshold

The reaction $e^+e^- \to W^+W^-$ produces a $W$-boson pair with a non-trivial spin correlation at threshold. This correlation leads to a characteristic angular correlation between the leptons produced in $W^{\pm} \to \ell ^{\pm} \nu$ (angles relative to the $e^-$ beam direction): $d \sigma /d \cos \theta_+ d \cos \theta_- \sim (1-\cos \theta_+) (1+ \cos \theta_-) (1+\cos \theta_- \cos \theta_+)$ . If only the $\ell^-$ is observed, its angular distribution is $d \sigma / d \cos \theta_- \sim (1+\cos \theta_-)(3-\cos \theta_-)$, implying a forward-backward asymmetry of 3/8. An analytic result is also given for the azimuthal correlation. These results are reproduced by a Monte Carlo program, that also enables us to study the effects of the $W$ decay width. The threshold behaviour, which stems from the dominance of $\nu$-exchange, is contrasted with that due to $\gamma$- and $Z$-exchange, which is relevant for annihilation in the helicity state $e^-_Re^+_L$.Comment: 10 pages, 6 figures, LaTeX, simpler derivation of main results, also added a comparison with Monte Carlo expectation

Absorption and photoluminescent spectra of dimethylaniline ethylene ketone dyes in isotropic solvents

Absorption and photoluminescent spectra of dimethylaniline ethylene ketone dyes of two types K1 and K2 in a series of isotropic solvents were studied. It was shown that the photoluminescent spectra depend both on nature of solvent (formation of associates with solvent owing to hydrogen bonds between the dye and alcohol or aggregates of dye molecules) and the dye concentration (concentration decay). The frequencies of electron transitions and frequency of intramolecular fluctuation were determined, and conclusions concerning the nature of absorption bands were made

Divergent reduplication as a phenomenon of linguistic creativity

The article analyzes reduction as a linguistic phenomenon and its role in the language game. Reduction exists in the vast majority of languages of the world. Despite of the existence of scientific studies of the graphic and phonetic originality of reduplicates in various languages, the content of these lexical units has not been sufficiently investigated. From the authors’ point of view, ignoring the pragmatic-communicative potential of reduplication creates a one-sided characteristic of this linguistic phenomenon. The role and functions of these language units in creating an aesthetic effect in communication are shown by examples of divergent reduplication. The authors distinguish some functions of divergent reduplication.В статье анализируется редупликация как лингвистический феномен и его роль в языковой игре. Редупликация существует в подавляющем большинстве языков мира. Несмотря на множество исследований графического и фонетического своеобразия редупликатов в различных языках, содержательная характеристика данных лексических единиц освещена недостаточно. Игнорирование прагматико-коммуникативного потенциала редупликации создает, по мнению авторов, однобокую характеристику данного лингвистического феномена. На примерах особого типа редупликации – дивергентной – показана роль и функции данных языковых единиц в создании эстетического эффекта в процессе коммуникации. Авторы выделяют ряд функций дивергентной редупликации

Clinical Comparative Study: Efficacy and Tolerability of Tolperisone and Thiocolchicoside in Acute Low Back Pain and Spinal Muscle Spasticity

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial Licens

Dielectric studies of dispersions of carbon nanotubes in liquid crystal 5CB

The frequency dependences of the imaginary ε″ and real ε′ parts of complex dielectric permittivity inherent to planarly aligned layers of nematic liquid crystals 5CB doped with multiwalled carbon nanotubes (CNT) were investigated in a wide range of frequencies (f = 10⁻²-10⁶ Hz) and CNT concentrations (c = 0-0.25 wt.%). It has been shown that the studied frequency range can be divided in three parts according to behavior of ε′ (f) and ε″ (f) curves. The low-frequency range (10⁻² < f < 10¹ Hz) reflects the near-electrode processes in the cell. The ratio ε″/ε′ used to characterize these processes sharply grows if the concentration of CNT exceeds 0.05 wt.%. The moderate frequency range (10¹ < f < 10⁵ Hz) corresponds to the alternating current conductivity, σАС. At the nanotubes concentration less than 0.025 wt.%, σАС does not depend on the frequency that implies its ionic origin. In its turn, at the c ≥ 0.025 wt.%, σАС is a power function of the frequency that is typical for electronic hopping mechanism. The transition from the ionic to electronic conductivity can be explained by the percolation theory with the critical concentration of nanotubes 0.031 wt.% and percolation parameter 2.5. The high-frequency range (10⁵ < f < 10⁶ ) is mainly attributed to dipole volume polarization. For c < 0.05 wt.% such polarization is well described by the Debye equation. The time of dielectric relaxation in this frequency range increases with nanotubes content. This is explained by effective interaction of nanotubes with 5CB molecules