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The $ΔI=1/2$ Rule for Kaons

Joaquim Prades
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Abstract

We report on recent advances at understanding the $ΔI= 1/2$ rule for kaons. We get reasonable matching between short-- and long--distances for scales between between 0.6 and 1.0 GeV and reproduce the $ΔI=1/2$ rule huge enhancement in the chiral limit. A detailed analysis of the different contributions to the relevant octet and 27-plet couplings is done. For the $B_6^{(1/2)}(μ) \equiv < (ππ)_0 | Q_6 | K > / [< (ππ)_0 | Q_6 | K > {\Large|}_{N_c}]$ parameter, we get in the chiral limit $B_6^{(1/2)}(μ) = 2.2 \pm 0.5$ for scales $μ\in [0.6, 1.0]$ GeV.

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Joaquim Prades. 1999-09-09. The $ΔI=1/2$ Rule for Kaons. https://doi.org/10.1016/s0920-5632(00)00578-8

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