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arXiv · hep-lat/0405028

Twisted mass QCD and lattice approaches to the $ΔI = 1/2$ rule

C. Pena·S. Sint·A. Vladikas
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Abstract

Twisted mass lattice QCD (tmQCD), generalised to four Wilson quark flavours, can be used for the computation of some weak matrix elements related to $ΔI=1/2$ transitions. Besides eliminating unphysical zero modes, tmQCD may alleviate long-standing renormalisation problems of the four-quark operators which contribute to CP-conserving $K\toπ$ transitions. With an active charm quark, the renormalisation of the $K\toπ$ matrix elements requires at most the subtraction of a linearly divergent counterterm. Furthermore, in the (partially) quenched approximation the twist angles can be chosen so that only a finite counterterm needs to be subtracted.

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C. Pena, S. Sint, A. Vladikas. 2004-10-22. Twisted mass QCD and lattice approaches to the $ΔI = 1/2$ rule. https://doi.org/10.1088/1126-6708%2F2004%2F09%2F069

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