Z-PHYSICS CONSTRAINTS ON VECTOR LEPTOQUARKS

We analyze the constraints on vector leptoquarks coming from radiative corrections to Z physics. We perform a global fitting to the LEP data including the oblique and non-universal contributions of the most gen eral effective Lagrangian for vector leptoquarks, which exhibits the S U(2)(L) x U(1)(Y) gauge invariance. We show that the Z physics leads t o stronger bounds on second and third generation vectors leptoquarks t han the ones obtained from low energy and the current collider experim ents. (C) 1997 Published by Elsevier Science B.V.