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arXiv · 1106.4539

The two-nucleon electromagnetic charge operator in chiral effective field theory ($\chi$EFT) up to one loop

S. Pastore·L. Girlanda·R. Schiavilla·M. Viviani
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Abstract

The electromagnetic charge operator in a two-nucleon system is derived in chiral effective field theory ($\chi$EFT) up to order $e\, Q$ (or N4LO), where $Q$ denotes the low-momentum scale and $e$ is the electric charge. The specific form of the N3LO and N4LO corrections from, respectively, one-pion-exchange and two-pion-exchange depends on the off-the-energy-shell prescriptions adopted for the non-static terms in the corresponding potentials. We show that different prescriptions lead to unitarily equivalent potentials and accompanying charge operators. Thus, provided a consistent set is adopted, predictions for physical observables will remain unaffected by the non-uniqueness associated with these off-the-energy-shell effects.

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S. Pastore, L. Girlanda, R. Schiavilla, M. Viviani. 2011-06-22. The two-nucleon electromagnetic charge operator in chiral effective field theory ($\chi$EFT) up to one loop. https://doi.org/10.1103/physrevc.84.024001

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