Violation Of The $\Delta I = 1/2$ Rule In $D \to \pi\pi$ Decays

Abstract

A strong violation of the $\displaystyle{\Delta I = {1\over 2}} $ rule has experimentally been found in the $\displaystyle{D \to \pi\pi}$ decays [1]. In this letter we will show that the order of magnitude of this violation can be understood in terms of the pure quantum chromo dynamics corrections to the weak interactions.