Rare K-decays and its strong constraints on the multi-scale walking technicolor model

The authors calculate the one-loop Z0-penguin contributions to the rare K-decays, K+→π+νν-bar, KL→π0νν-bar and KL→μ+μ-, from the unit-charged pseudo-Goldstone bosons π1 and π8 in the framework of the Multi-scale Walking Technicolor Model. The authors find that: (a) the π1 and π8 can provide one to three orders enhancements to the branching ratios of the rare K-decays under study; (b) the assumed mass ranges of the unit-charged PGBs in the Multi-scale Walking Technicolor Model are excluded by the rare K-decay data. According to this and other relevant studies, one finds that the Multi-scale Walking Technicolor Model are conflict with the data and therefore excluded