LOOP EFFECTS OF EXOTIC LEPTONS ON VECTOR-BOSON PAIR PRODUCTION AT E(-) COLLIDERS()E()

We study the quantum effects of exotic heavy leptons on the production of two vector bosons in e(+)e(-) annihilation. We present closed anal ytic expressions for vector-boson self-couplings and differential cros s sections, within the framework of two favorable new-physics scenario s: (i) the fourth-generation Majorana-neutrino model and (ii) an E-6-i nspired model with sequential mirror isodoublets. We constrain these m odels by requiring that their contributions to the oblique electroweak parameters be compatible with a recent global fit to high-precision d ata. We then systematically analyze the loop-induced deviations in the CERN LEP2 cross section of e(+)e(-)-->W+W- predicted by the models th us confined.