CONSTRAINTS ON THE PARAMETERS OF THE LEFT-RIGHT MIRROR MODEL

We study some phenomenological constraints on the parameters of a left -right model with mirror fermions that solves the strong CP problem. I n particular, we evaluate the contribution of mirror neutrinos to the invisible Z decay width (Gamma(Z)(inv)), and we find that the present experimental value on Gamma(Z)(inv), can be used to place an upper bou nd on the Z-Z' mixing angle that is consistent with limits obtained pr eviously from other low-energy observables. In this model the charged fermions that correspond to the standard model mix with its mirror cou nterparts. This mixing, simultaneously with the Z-Z' one, leads to mod ifications of the Gamma(Z-->f (f) over bar) decay width. By comparing with CERN LEP data, vie obtain bounds on the standard-mirror lepton mi xing angles. We also find that the bottom quark mixing parameters can be chosen to fit the experimental values of R-b, and the resulting val ues for the Z-Z' mixing angle do not agree with previous bounds. Howev er, this disagreement disappears if one takes the more recent ALEPH da ta.