arXiv:hep-lat/0507033·v1·High Energy Physics — Lattice
One-loop matching of Delta S=2 four-quark operators with improved staggered fermions
Thomas Becher (Fermilab)🇺🇸 · Elvira Gamiz (Glasgow U.)🇬🇧 · Kirill Melnikov (Hawaii U.)🇺🇸
Abstract
We compute O(alpha_s) lattice-to-continuum perturbative matching coefficients for the Delta S=2 flavor changing four-quark operators for the Asqtad improved staggered action. In conjunction with lattice simulations with three flavors of light, dynamical quarks, our results yield an unquenched determination of B_K, the parameter that determines the amount of indirect CP violation in the neutral kaon system. Its value is an important input for the unitarity triangle analysis of weak decays.
Comments: 11 pages, 2 figures