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arXiv · hep-ph/9511465

Weak $K$--Amplitudes in the Chiral and $1/N_c$--Expansions

A. Pich·E. de Rafael
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Abstract

It is shown that there exist symmetry constraints for non--leptonic weak amplitudes which emerge when the $1/N_c$--expansion restricted to the leading and next--to--leading approximations only is systematically combined with $χ$PT limited to the lowest non--trivial order. We discuss these constraints for the couplings $\mbox{\bf g}_8$ and $\mbox{\bf g}_{27}$ of $ΔS=1$ transitions and the $\mbox{\bf B}_{K}$--parameter of $K^0-{\bar K}^0$ mixing.

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A. Pich, E. de Rafael. 1995-11-30. Weak $K$--Amplitudes in the Chiral and $1/N_c$--Expansions. https://doi.org/10.1016/0370-2693(96)00171-2

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