B. Akkus et al., THE RARE Z-]J PSI(UPSILON)+X DECAYS IN SU(2)XU(1)XU(1) GAUGE-THEORIES/, Nuovo cimento della Società Italiana di Fisica. A. Nuclei, particles and fields, 107(9), 1994, pp. 1723-1727
In the framework of the SU(2) x U(1) x U(1) gauge model the rare decay
s Z --> J/psi(gamma) + X (where X is the light gauge boson correspondi
ng to the extra U(1) group) are investigated. Using the model of indep
endent restrictions to the coupling constant and mass of X-boson, it i
s shown that, in some region of parameters, these decay rates (greater
-than-or-equal-to 10 keV) can be measurable in LEP with high luminosit
y.