Determination of the Dalitz plot parameter α for the decay η → 3 π0 with the crystal ball at MAMI-B

Abstract

A precise measurement of the Dalitz plot parameter, α , for the η → 3*pi;0- decay is presented. The experiment was performed with the Crystal Ball and TAPS large-acceptance photon detectors at the tagged photon beam facility of the MAMI-B electron accelerator in Mainz. High statistics of 1.8 • 106 η → 3 π0 events were obtained, giving the result α = - 0.032±0.002 stat±0.002syst . © 2009 SIF, Springer-Verlag Berlin Heidelberg.