Study of the ηπ[sup 0] system in the mass range up to 1200 MeV

Abstract

The reaction π − p → ηπ o n has been studied with GAMS-2000 spectrometer in the secondary 38 GeV/c π − -beam of the IHEP U-70 accelerator. Partial wave analysis of the reaction has been performed in the ηπ o mass range up to 1200 MeV. The a 0 (980)-meson is seen as a sharp peak in S-wave. The t-dependence of a 0 (980) production cross section has been studied. Dominant production of the a 0 (980) at a small transfer momentum t confirms the hypothesis of Achasov and Shestakov about significant contribution of the ρ 2 exchange (I G J P C = 1 + 2 −− ) in the mechanism of a 0 (980) meson production in t-channel of the reaction.