Bounds on scalar leptoquarks from Z-physics Original Research Article

We analyse the constraints on scalar leptoquarks coming from radiative corrections to Z-physics. We perform a global fitting to the LEP data including the contributions of the most general effective Lagrangian for scalar leptoquarks, which exhibits the SU(2)L × U(1)Y gauge invariance. We show that the bounds on leptoquarks that couple to the top quark are much stronger than the ones obtained from low energy experiments.