HQET chromomagnetic interaction at two loops
arXiv:hep-ph/9701415 · doi:10.1016/S0370-2693(97)00587-X 10.1016/j.physletb.2007.05.016
Abstract
We present the coefficient of the chromomagnetic interaction operator, the only unknown coefficient in the Heavy Quark Effective Theory (HQET) lagrangian up to the $1/m$ level, with the two-loop accuracy by matching scattering amplitudes of an on-shell heavy quark in an external field in full QCD and HQET, and obtain the two-loop anomalous dimension of this operator in HQET.
10 pages, LaTeX2e, 2 eps figures included. Revised discussion of (n_f-1)-flavour HQET included