6533b82afe1ef96bd128ca38

RESEARCH PRODUCT

Strong Enhancement ofɛ′/ɛthrough Final State Interactions

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description

We quantify the important effect of strong final state interactions in the weak $K\ensuremath{\rightarrow}2\ensuremath{\pi}$ amplitudes, using the measured $\ensuremath{\pi}\ensuremath{-}\ensuremath{\pi}$ phase shifts with $J\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0$ and $I\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0,2$. The final rescattering of the two pions provides a strong enhancement of the $\ensuremath{\Delta}I\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1/2$ amplitude, which so far has been neglected in the theoretical predictions of ${\ensuremath{\varepsilon}}^{\ensuremath{'}}/\ensuremath{\varepsilon}$. This correction increases the standard model prediction of ${\ensuremath{\varepsilon}}^{\ensuremath{'}}/\ensuremath{\varepsilon}$ to values in good agreement with the experimental measurements.