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 Poincare 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 numberA > 2, and their impact on EFT calculations of binding energies and scattering observables in these systems should be studied.
Relativity constraints on the two-nucleon contact interaction
GIRLANDA, Luca;
2010-01-01
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 Poincare 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 numberA > 2, and their impact on EFT calculations of binding energies and scattering observables in these systems should be studied.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
