The power of effective field theories in nuclei: The deuteron, NN scattering and electroweak processes

We show how effectively effective quantum field theories work in nuclear ph ysics. Using the physically transparent cut-off regularization, we study th e simplest nuclear systems of two nucleons for both bound and scattering st ates 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 fus ion process p + p --> d + e(+) + nu(e), and we demonstrate that these are a ll described with great accuracy in the expansion to the next-to-leading or der, 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. (C) 1999 Els evier Science B.V.