The Minimal Quark-Lepton Symmetry Model and the Limit on Z'-mass

Abstract

A minimal extension of the Standard Model containing the four-color quark-lepton symmetry is proposed and discussed. The existence of a rather light extra $Z^{\prime }$-boson originated from the four-color quark-lepton symmetry is shown to be compatible with the current electroweak data. The cross sections $\sigma (e^{+}{e}^{-}\to \gamma ,Z,Z^{\prime }\to \bar{f}f)$ are calculated, and their deviations from the SM predictions are shown to be significant at $\sqrt{s}\ge 200GeV$ and available for the measurements at the LEP200 and future colliders.

Comments: 15 pages, LaTeX, 1 figure available on request; to be published in Phys. Lett. B