H-0(F)OVER-BAR-F AND Z(F)OVER-BAR-F INTERACTIONS IN THE EFFECTIVE LAGRANGIAN APPROACH

We study possible effects induced by decoupled physics beyond the stan dard model on the decays Z--><(f)over bar f> and H-0--><(f)over bar f> in the framework of effective Lagrangians, We consider only those dim ension 6 [SUL(2)xU(Y)(1)]-invariant fermionic operators that may be ge nerated at tree level by the underlying physics. Using electroweak dat a, we get constraints on low energy new physics contributions to the p artial widths Gamma(Z--><(f)over bar f>), including leptonic FCNC effe cts. We also discuss the underlying physics effects induced on BR(H-0- -><(f)over bar f>) of light fermions. In particular, we find a remarka ble enhancement of the <(e)over bar e>, <(u)over bar u> and ,<(d)over bar d> channels.