The Power Of Effective Field Theories In Nuclei: The Deuteron, NN Scattering and Electroweak Processes

TL;DR

This paper demonstrates the high effectiveness of effective field theories in describing simple nuclear systems, including bound states, scattering, and electroweak processes, with accurate results at low energies.

Contribution

It shows how effective field theories, with a transparent regularization, accurately describe nuclear phenomena and explores the role of pions as a new degree of freedom in the theory.

Findings

Accurate description of deuteron properties and nucleon scattering phase-shifts.

Successful modeling of thermal neutron-proton capture and solar proton fusion.

Validation of effective field theory expansion at next-to-leading order.

Abstract

We show how effectively effective quantum field theories work in nuclear physics. Using the physically transparent cut-off regularization, we study the simplest nuclear systems of two nucleons for both bound and scattering states at a momentum scale much less than the pion mass. We consider all the static properties of the deuteron, the two-nucleon scattering phase-shifts, the n + p --> d + \gamma process at thermal energy and the solar proton fusion process p + p --> d + e(+) + \nu(e), and we demonstrate that these are all described with great accuracy in the expansion to the next-to-leading order. We explore how a "new" degree of freedom enters in an effective theory by turning on and off the role of the pion in the Lagrangian.