Technicolor Theories with Negative S

Abstract

We show that the pseudo Nambu--Goldstone boson contribution to the Peskin--Takeuchi electroweak parameter $S$ can be negative in a class of technicolor theories. This negative contribution can be large enough to cancel the positive techni-hadron contribution, showing that electroweak precision tests alone cannot be used to rule out technicolor as the mechanism of electroweak symmetry breaking.Comment: (LBL-32893, UCB-PTH 92/34, 10 pages; we added a discussion of uncertainties, fine-tuning, and SU(2) asymptotic freedom; the conclusions are unchanged.