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

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.