Poincare' invariance constraints on non-relativistic effective field theories

Abstract

We discuss Poincare' invariance in the context of non-relativistic effective field theories of QCD. We show, in the cases of the HQET and pNRQCD, that the algebra of the generators of the Poincare' transformations imposes precise constraints on the form of the Lagrangian. In the case of the HQET they are the relations formerly obtained by reparametrization invariance.

Comments: 6 pages, espcrc2.sty; typo in Eq. (29) corrected. Talk given at QCD03, 2-9 July, Montpellier, France To be published in Nucl. Phys. Proc. Suppl