Oxidation of trans-alloocimene by thallium(III) nitrate

We have obtained 2,7-dimethoxy-2,7-dimethyl-3,5-octadiene by the action of thallium(III) nitrate on trans-allo-ocimene. © 1990 Plenum Publishing Corporation

Update of the e^+e^-\to\pi^+\pi^- cross section measured by SND detector in the energy region 400<\sqrt{s}<1000 MeV

The corrected cross section of the e^+e^-\to\pi^+\pi^- process measured in the SND experiment at the VEPP-2M e^+e^- collider is presented. The update is necessary due to a flaw in the e^+e^-\to\pi^+\pi^- and e^+e^-\to\mu^+\mu^- Monte Carlo events generators used previously in data analysis.Comment: 10 pages,7 figure

The quasiclassical theory of the Dirac equation with a scalar-vector interaction and its applications in the theory of heavy-light mesons

We construct a relativistic potential quark model of $D$, $D_s$, $B$, and $B_s$ mesons in which the light quark motion is described by the Dirac equation with a scalar-vector interaction and the heavy quark is considered a local source of the gluon field. The effective interquark interaction is described by a combination of the perturbative one-gluon exchange potential $V_{\mathrm{Coul}}(r)=-\xi/r$ and the long-range Lorentz-scalar and Lorentz-vector linear potentials $S_{\mathrm{l.r.}}(r)=(1-\lambda)(\sigma r+V_0)$ and $V_{\mathrm{l.r.}}(r)=\lambda(\sigma r+V_0)$, where $0\leqslant\lambda<1/2$. Within the quasiclassical approximation, we obtain simple asymptotic formulas for the energy and mass spectra and for the mean radii of $D$, $D_s$, $B$, and $B_s$ mesons, which ensure a high accuracy of calculations even for states with the radial quantum number $n_r\sim 1$. We show that the fine structure of P-wave states in heavy-light mesons is primarily sensitive to the choice of two parameters: the strong-coupling constant $\alpha_s$ and the coefficient $\lambda$ of mixing of the long-range scalar and vector potentials $S_{\mathrm{l.r.}}(r)$ and $V_{\mathrm{l.r.}}(r)$. The quasiclassical formulas for asymptotic coefficients of wave function at zero and infinity are obtained.Comment: 22 pages, 6 figure

Radiative corrections for pion and kaon production at e+e−e^+e^- colliders of energies below 2 GeV

Processes of electron-positron annihilation into charged pions and kaons are considered. Radiative corrections are taken into account exactly in the first order and within the leading logarithmic approximation in higher orders. A combined approach for accounting exact calculations and electron structure functions is used. An accuracy of the calculation can be estimated about 0.2%.Comment: 16 pages, LaTeX, epsfig.sty, 3 PostScript figure

Large angle QED processes at e^+e^- colliders at energies below 3 GeV

QED processes at electron-positron colliders are considerd. We present differential cross-sections for large-angle Bhabha scattering, annihilation into muons and photons. Radiative corrections in the first order are taken into account exactly. Leading logarithmic contributions are calculated in all orders by means of the structure-function method. An accuracy of the calculation can be estimated about 0.2%.Comment: 24 pages, LaTeX, 2 PS figures, numerical results for large-angle Bhabha are adde

Current tensor with heavy photon for hard pair production by longitudinally polarized electron

The electron current tensor for the scattering of heavy photon on longitudinally polarized electron accompanied with additional hard electron-positron pair has been considered. The contribution of collinear and semicollinear kinematics is computed. The full analysis of both, spin-dependent and spin-independend parts of electron current tensor, is performed. The obtained result allows to calculate the corresponding contribution into the second order radiative correction to cross-sections of different processes with the next-to-leading accuracy.Comment: 19p,2Fig. (Submitted to Journ.of Physics G

Radiative Corrections to Polarized Inelastic Scattering in Coincidence

The coplete analysis of the model-independent leading radiative corrections to cross-section and polarization observables in semi-inclusive deep-inelastic electron-nucleus scattering with detection of a proton and scattered electron in coincidence has been performed. The basis of the calculations consists of the Drell-Yan like representation in electrodynamics for both spin-independent and spin-dependent parts of the cross-section in terms of the electron structure functions. The applications to the polarization transfer effect from longitudinally polarized electron beam to detected proton as well as to scattering by the polarized target are considered.Comment: 18p, to be published in JET

Small angle Bhabha scattering for LEP

We present the results of our calculations to a one, two, and three loop approximation of the e^+e^-\rightarrow e^+e^- Bhabha scattering cross-section at small angles. All terms contributing to the radiatively corrected cross-section, within an accuracy of \delta\sigma/ \sigma = 0.1 \% , are explicitely evaluated and presented in an analytic form. O(\alpha) and O(\alpha^2) contributions are kept up to next-to-leading logarithmic accuracy, and O(\alpha^3) terms are taken into account to the leading logarithmic approximation. We define an experimentally measurable cross-section by integrating the calculated distributions over a given range of final-state energies and angles. The cross-sections for exclusive channels as well as for the totally integrated distributions are also given