Once more on extra quark-lepton generations and precision measurements

Abstract

Precision measurements of $Z$-boson parameters and $W$-boson and $t$-quark masses put strong constraints on non $SU(2)\times U(1)$ singlet New Physics. We demonstrate that one extra generation passes electroweak constraints even when all new particle masses are well above their direct mass bounds.

Comments: Dedicated to L.B. Okun's 80th birthday