Search for a four-pion resonance, and some decay modes of the ρ and ω-mesons

A search for four-pion resonances among six-prong annihilations of 1.61 GeV/c antiprotons in the Berkeley 72 in. hydrogen bubble chamber has been made. No four-body decays of the ρ or ω mesons have been observed and upper limits for these decays are quoted. The fraction of the charged ρ mesons which decay via ρ±→η+π± is determined to be (1.2±2)%, in agreement with a positiveG parity assignment for the η. The neutral four-pion effective mass distribution shows a suggestive, but inconclusive, peak at 1.04 GeV.