Radiative decay width of the a2(1320)^- meson
Abstract
Coherent pi^+pi^-pi^- production in the interactions of a beam of 600 GeV pi^- mesons with C, Cu and Pb nuclei has been studied with the SELEX facility (Experiment E781 at Fermilab). The a2(1320) meson signal has been detected in the Coulomb (low q^2) region. The Primakoff formalism used to extract radiative decay width of this meson yields Gamma=284+/-25+/-25 keV, which is the most precise measurement to date.