Non-trivial Test of Electroweak Quantum Effects

Abstract

Based on recent $W$-mass measurements, the electroweak theory is tested at non-trivial quantum correction level, i.e., beyond the Born approximation with $\alpha(M_Z)$ instead of $\alpha$. We can conclude that some non-Born type corrections must exist at more than 92 % confidence level, and the non-decoupling top-quark corrections are required at 97 % confidence level.