Non-Universal Correction To Z→b b ¯ And Flavor Changing Neutral Current Couplings
Abstract
A non-universal interaction associated with top quark induces flavor changing neutral currents (FCNC) among light fermions. The size of the FCNC effect depends crucially on the dynamics of the fermion mass generation. In this paper, we study the effect of a non-universal interaction on
Zbb
,
Zbs
{\it etc}, by using an effective lagrangian technique and assuming the quark mass matrices in the form of a generalized Fritzsch ansatz. We point out that if fitting
R
b
to the LEP data within
1σ
, the induced FCNC couplings are very close to the experimental limits.