What hath Weinberg wrought? Reflections on what Weinberg's papers on 'Nuclear Forces from Chiral Lagrangians' did and did not accomplish

Abstract

I discuss selected legacies of Weinberg's application of chiral Lagrangians to nuclear physics: (1) the use of the chiral expansion to organize the interaction of pions and photons with a nucleus; (2) the much-debated question of why and how the potential derived from a chiral Lagrangian should be inserted in the Schrodinger equation; (3) the emergence of "pionless EFT" as a tool for diagnosing universal correlations that are present in quantum few-body systems of very different sizes, and, perhaps most important of all, (4) an epistemological shift in what is expected of a nuclear-physics calculation.

Comments: 20 pages, 3 figures. Contribution to Special Issue of Few-Body Systems: Celebrating 30 years of Steven Weinberg's papers on Nuclear Forces from Chiral Lagrangians. v2: Contains updated discussion of M_N scaling and corrects statements in v1 about Weinberg's choice of regularization and subtraction scheme. v3: Version accepted for publication. Includes additional references to recent work