Limits on nonstandard top quark couplings from electroweak measurements.

We calculate the typical size of loop corrections to electroweak observables arising from non-standard Ztt and Wtb vertices. We use an effective Lagrangian formalism based on the electroweak gauge group SU(2)L× U(1)Y → U(1)EM . Limits on the non-standard model top quark couplings from electroweak observables are presented and compared with previously obtained limits. ∗This manuscript has been authored under contract number DE-AC02-76CH00016 with the U.S. Department of Energy. Accordingly, the U.S. Government retains a non-exclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. Government purposes.