Low-energy hadron physics from effective chiral Lagrangians with vector mesons

Abstract

We review the use of effective chiral Lagrangians with vector mesons in the description of low-energy hadron physics. The massive Yang-Mills approach (vector mesons as heavy gauge particles of the Yang-Mills type) and the hidden symmetry scheme (vector mesons as dynamical gauge bosons) used to enlarge the field space beyond the Goldstone pions are discussed in detail, with particular emphasis on the gauged Wess-Zumino action and Vector Meson Dominance. It is demonstrated how all parameters can be fixed in the meson sector, and in particular, that there are only a few. The equivalence of these two seemingly different approaches is proven. The QCD generating functional is investigated and its connection to effective theories of spin-0 and spin-1 mesons is shown. Baryons arise as topological solitons, with all parameters fixed in the meson sector. We present in great detail the phenomenological aspects of nucleons such as their static properties, electromagnetic, axial and strong form factors. The close connection to boson-exchange is elucidated, and the application to N N -physics is stressed. We furthermore discuss the inclusion of scalar particles and their relevance to QCD as well as the problem of nuclear binding. Further developments are sketched.