# TTP97-04 HQET chromomagnetic interaction at two loops

TTP97-04 HQET chromomagnetic interaction at two loops

TTP97-04 HQET chromomagnetic interaction at two loops

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.

 Andrzej Czarnecki and Andrey Grozin Phys. Lett. B405 142 1997 PDF PostScript arXiv