A dynamical principle for 3D-4D interlinkage in Salpeter-like equations

Abstract

The half-century old Markov-Yukawa Transversality Principle (MYTP) which provides a theoretical rationale for the covariant instantaneous approximation (CIA) that underlies all Salpeter-like equations, is generalized to a covariant null-plane ansatz (CNPA). A common characteristic of both formulations is an exact 3D-4D interlinkage of BS amplitudes which facilitates a two-tier description: the 3D form for spectroscopy, and the 4D form for transition amplitudes as 4D loop integrals. Some basic applications of MYTP on the covariant null plane (quark mass function, vacuum condensates, and decay constants) are given on the lines of earlier applications to these processes under CIA.