Four Fermion Operator Matching with NRQCD Heavy and AsqTad Light Quarks

Abstract

We present one-loop matching coefficients between continuum and lattice QCD for the heavy-light four-fermion operators relevant for neutral B meson mixing both within and beyond the Standard Model. For the lattice theory we use nonrelativistic QCD (NRQCD) to describe b quarks and improved staggered fermions (AsqTad) for light quarks. The gauge action is the tree-level Symanzik improved gauge action. Matching to full QCD is carried out through order alpha_s, Lambda_{QCD}/M_b, and alpha_s/(aM_b).