• A.V. Kuznetsov and N.V. Mikheev
    New Type of Mixing in the Minimal Quark-Lepton Symmetry and a Lower Bound on the Vector-Leptoquark Mass
    Yadernaya Fizika, 1995, V. 58, N 12, P. 2228-2234.
    [Physics of Atomic Nuclei, 1995, V. 58, N 12, P. 2113-2119.]

    • Abstract

    Some low-energy implications of the minimal extension of the standard model based on Pati-Salam quark-lepton $SU(4)_V \otimes SU(2)_L \otimes G_R$ symmetry is analyzed. It is shown that, if this symmetry is realized, it is necessary to consider a new type of mixing in the interactions of the SU(4)V leptoquarks with quarks and leptons. The resulting additional arbitrariness of the choice of parameters make it possible to substantially reduce the lower limit on the vector-leptoquark mass MX from $\pi$ and K decays and $\mu e$ conversion. The only mixing-independent constraint stems from a cosmological estimate of $\pi^0 \to \nu \bar{\nu}$ decay width and is MX > 18 TeV.

    ÿ