Measurement of the Cross Section for the Process $${e^{+}e^{-}}{\to}{K}^{{+}}{K}^{{-}}{\pi}^{{0}}$$ with the SND Detector at Collision Energies of $$\sqrt{{s}}{=}{1.3{-}2.0}$$ GeV in the Center-of-Mass Frame

Physics of Atomic Nuclei - In an experiment with the SND detector at the VEPP-2000 $$e^{+}e^{-}$$ collider, the cross sections for the processes $$e^{+}e^{-}\to K^{+}K^{-}\pi^{0}$$ and...     

Study of the Process $${e}^{{+}}{e}^{{-}}{\to}{\eta\pi}^{{0}}{\gamma}$$ in the Cossision-Energy Range of $$\sqrt{{s}}{=}{1.05{-}2.00}$$ GeV

Physics of Atomic Nuclei - The process $$e^{+}e^{-}\to\eta\pi^{0}\gamma$$ is studied in the range of center-of-mass (c.m.) collision energies between 1.05 and 2.00 GeV on the basis of data...     

Resonance Raman spectroscopy of polyene compounds (multimode systems). Polyacetylene synthesized from cyclooctatetraene

Specific features of the excitation spectra of resonance Raman (RR) lines in multimode systems were characterized. Based on this, the spectra, the structure, and the composition of polyacetylene (PA) synthesized by polymerization of cycloocta-1,3,5,7-tetraene in the presence of metathesis catalysts were investigated. A dependence of frequencies and intensities of the C-C and C=C stretching lines on the exciting light wavelength was found and explained by broad distribution of defect-free conjugated polymer segments in the PA samples studied on the number of double bonds incorporated in them. A procedure for the calculation of the distribution functions and of the shapes of RR lines was proposed. These functions are bimodal. A reversiblecis-trans-transition was discovered in the PA samples not subjected to heat treatment, which was attributed to the presence of macrocyclic polyene structures.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 2016–2020, August, 1996.     

Molecular magnetic dichroism in spectra of white dwarfs

We present novel calculations of the magnetic dichroism appearing in molecular bands in the presence of a strong magnetic field, which perturbs the internal structure of the molecule and results in net polarization due to the Paschen-Back effect. Based on that, we analyze new spectropolarimetric observations of the cool magnetic helium-rich white dwarf G99-37, which shows strongly polarized molecular bands in its spectrum. In addition to previously known molecular bands of the C2 Swan and CH A-X systems, we find a firm evidence for the violet CH B-X bands at 390 nm and C2 Deslandres-d'Azambuja bands at 360 nm. Combining the polarimetric observations with our model calculations, we deduce a dipole magnetic field of 7.5+/-0.5 MG with the positive pole pointing towards the Earth. We conclude that the developed technique is an excellent tool for studying magnetic fields on cool magnetic stars.     

Searching for the process e+e- → K+K-π0 in experiments with the spherical neutral detector at VEPP-2M

We have searched for the process e⁺e^- → K⁺K^-π⁰ at energies up to 1.38 GeVin an experiment with the spherical neutral detector at the VEPP-2M e⁺e^- collider. The upper limits of the cross sections for the processes σ(e⁺e →; φπ: → K⁺K^-π⁰) < 0.023 nb and σ(e⁺e^- → KK*(892) → K⁺K^-π⁰) < 0.059 nb have been established at a 95% confidence level.     

Measurement of the relative probability of the decay φ → η′γ in the channel η′ → ηπ0π0, η → γγ

The process e ⁺ e ^? → η′γ, η′ → η π⁰π⁰, η → γγ is investigated by an SND detector in experiment on a VEPP-2M equipment with colliding electron-positron beams. The analysis of experimental data yields a value of B(? → η′γ)=(6.7 _?4.2 ^+5.0 ±1.5)×10^?5 for the decay probability. Taking into account a previous measurement of this quantity by an SND detector in the decay channel η′ → π⁺π^?η, one finally obtains B(?→η ′γ)=(6.7 _?2.4 ^+2.8 ±0.8)×10^?5.     

Measurement of the ϕ → π0 e + e − decay probability

The measurement of the ? → π⁰ e ⁺ e ^? conversion decay probability on the SND detector at the VEPP-2M e ⁺ e ^? collider gave the value Br(? → π ⁰ e ⁺ e ^?) = (1.01 ± 0.28 ± 0.29) × 10^?5.     

Identification of absorption bands corresponding to C-C1 stretching vibrations in the IR spectra of organic compounds

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 55, No. 3, pp. 392–396, September, 1991.     

Raman spectral study of poly(p-phenylene) and related oligomers

Raman spectroscopy was used to study the structure of two samples of poly(p-phenylene) (PP) and related oligomers. The ratio of the intensities of the bands at 1600 and 1280 cm^–1 increases linearly with extension of the chain and may be used for characterization of these macromolecules. Quinoid forms were found for heat-treated samples of PP and dodecaphenyl. These forms are apparently related to the effect of catalyst residues and subsequent heating.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2167–2170, September, 1990.