Longitudinal phase space and helicity conservation in diffractive resonance production

Abstract

Recent experimental results on helicity conservation in A 1 production are examined using a Reggeized Deck model similar to that proposed by Berger. It is shown that this model, which conserves neither s-channel nor t-channel helicity, is able to reproduce the isotropic azimuthal distributions found experimentally, when the events are selected according to their location on a longitudinal phase space (LPS) plot. The approximate isotropy of these distributions cannot be considered as conclusive evidence in favor of helicity conservation, and it pointed out that the “LPS-selection” of events can hide important features of the experimental results.