Cross sections for resonance production in the reaction π±p → p π±π+π− at 16 GeV/ c, as obtained by a maximum likelihood fit : Aachen-Berlin-Bonn-CERN-Heidelberg Collaboration

Abstract

Cross sections for resonance production in the reactions π ±p → p π ± π + π − at 16 GeV/ c are determined by a maximum likelihood fit, making use of the measurements of all individual events. The reactions are described by a simple parametrization based on an incoherent superposition of amplitudes for quasi two-body and quasi three-body processes and a non-resonant backgroud. In this way the reflections are accounted for in a consistent way. Thus cross sections are obtained for Δ ++, Δ 0, ρ 0 and f 0 production which do not suffer from the uncertainties of background subtraction typical of the usual technique of fitting individual mass distributions.