Phenomenological mass limits on extraZofE6superstrings

Abstract
We fit low-energy and pp¯ collider data with a model based on a Su(2)⊗U(1)⊗U(1) electroweak group, where the additional U(1) arises from E6 as required by symmetry breaking in some superstring models. We find that the extra Z must have a mass greater than 143 GeV if its decays to exotic fermions are kinematically suppressed. The production and decays of this boson are discussed.