Search

Partial widths and double- and single-differential distributions are calculated on the framework of the Standard Model for the four-lepton decays , where = and . The contribution of virtual-photon emission by a light quark and a heavy quark, the bremsstrahlung contribution from charged leptons in the final state, the weak-annihilation contribution, and the contribution of wide vector resonances are taken into account. The contribution of narrow and resonances is excluded. Virtual-photon emission by the light quark of a meson is described on the framework of the vector-meson-dominance model, within which only the contributions of the lightest vector mesons containing pairs are taken into account. For the meson, this is the resonance. For the meson, the contributions of the and resonances are taken into account. Two possibilities are considered in the present study. The first is that where the contributions of the narrow and mesons are excluded from the partial widths with respect to the corresponding decays. The second is that where the contributions of narrow resonances are taken into account in partial widths. The problem of the influence of the subtraction procedure on the partial widths with respect to the decays is studied individually. [ABSTRACT FROM AUTHOR]

The work is devoted to the transverse polarization () of -hyperons and corresponding antihyperons produced in meson–proton and meson–nuclear interactions in inclusive reactions. The currently available experimental data are compared with calculations based on the chromomagnetic polarization of quark (CPQ) model. The main features of the CPQ model are the prediction of hyperon polarization oscillations depending on the Feynman variable in the case of a sufficiently strong chomomagnetic field and resonant dependence of the polarization on the c.m. energy () for some reactions. Calculations based on the CPQ model were performed for still unexplored kinematic regions and various targets and can be tested in the SPASCHARM experiment at the NRC "Kurchatov Institute"—IHEP. [ABSTRACT FROM AUTHOR]