Dispersion Theory and Current Algebra
Abstract
Lorentz invariance and the basic assumption in dispersion theory, namely, that the matrix element of a retarded or advanced commutator of local fields is an analytic function of the energy variable, are seen to determine the method of handling the dispersion integral, and to require the matrix element to consist of terms, each of which is a product of at most two poles or an integral thereof. This method is used to study currentalgebra commutators, with the consequence that the widely employed assumption of singlepole dominance for the spin1 parts of vector or axialvector currents is inconsistent with current algebra. Some aspects of the K_{l3} form factors are also discussed.
 Publication:

Physical Review D
 Pub Date:
 July 1971
 DOI:
 10.1103/PhysRevD.4.517
 Bibcode:
 1971PhRvD...4..517L