A COMPLETE HEAVY QUARK EFFECTIVE LAGRANGIAN FROM QCD

Abstract

We show how to construct a heavy quark effective Lagrangian which contains both ‘particle fields’ and ‘antiparticle fields’. This differs from the previous constructed heavy quark effective Lagrangian which includes only one of these fields. The Lorentz invariant of the full QCD theory trivially implies that of this effective Lagrangian without the need of summing over the velocity. This effective Lagrangian is reparametrization invariant for an arbitrary velocity. In particular our form of effective Lagrangian permits an expansion in powers of the heavy quark momenta characterizing its off-shellness divided by its mass.