Year: 2010
Type: article
Abstract: We construct the most general, relativistically invariant, contact Lagrangian at order ${Q}^{2}$ in the power counting, with $Q$ denoting the low momentum scale. A complete, but nonminimal, set of (contact) interaction terms is identified, which upon nonrelativistic reduction generate two leading independent operator combinations of order ${Q}^{0}$ and seven subleading ones of order ${Q}^{2}$---a result derived previously in the heavy-baryon formulation of effective field theories (EFTs). We show that Poincar\'e covariance of the theory requires that additional terms with fixed coefficients be included, to describe the two-nucleon potential in reference frames other than the center-of-mass frame. These terms will contribute in systems with mass number $A>2$, and their impact on EFT calculations of binding energies and scattering observables in these systems should be studied.
Source: Physical Review C
Authors: L. Girlanda, S. Pastore, R. Schiavilla, M. Viviani
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2005751475