K-->pipi amplitudes from lattice QCD with a light charm quark

Abstract

We compute the leading-order low-energy constants of the DeltaS=1 effective weak Hamiltonian in the quenched approximation of QCD with up, down, strange, and charm quarks degenerate and light. They are extracted by comparing the predictions of finite volume chiral perturbation theory with lattice QCD computations of suitable correlation functions carried out with quark masses ranging from a few MeV up to half of the physical strange mass. We observe a large DeltaI=1/2 enhancement in this corner of the parameter space of the theory. Although matching with the experimental result is not observed for the DeltaI=1/2 amplitude, our computation suggests large QCD contributions to the physical DeltaI=1/2 rule in the GIM limit, and represents the first step to quantify the role of the charm quark-mass in K-->pipi amplitudes.

4 pages, 1 figure. Minor modifications. Final version to appear on PRL

References in corpus (2)

• Non-perturbative renormalisation of left-left four-fermion operators with Neuberger fermions
• Quenched penguins and the Delta I=1/2 rule

Cited by in corpus (6)

• Probing the chiral regime of Nf=2 QCD with mixed actions
• The Large $N_c$ limit of QCD on the lattice
• Non-perturbative renormalisation of left-left four-fermion operators with Neuberger fermions
• Non-leptonic kaon decays at large $N_c$
• Twisted mass QCD for weak matrix elements
• Towards a quantitative understanding of the Delta I=1/2 rule