ϑ(1700) and ξ(2230) resonances in the π−p→K s0K s0n reaction at momentum 40 GeV/ c

Abstract

The reaction π −p→K s 0K s 0n was studied at the incident momentum 40 GeV/ c making use of the 6 m magnetic spark spectrometer MSS ITEP. Partial wave analysis was carried out using ∼ 6700 events of this reaction with t′<0.2 (GeV/ c) 2. In D 0 wave ( J PC =2 ++) we find three states besides the well-known resonances f(1270) and f′(1525): ϑ(1700) with the width 30 MeV, f″(1980) with the width 145 MeV (very likely a radial excitation of the f′(1525) meson) and ξ(2230) with the width 80 MeV. The measured width of the ϑ-meson is somewhat smaller, and that of the ξ-meson is somewhat higher than the known values from J ψ radiative decays. In S wave ( J PC =0 ++) we find the known states ϵ′(1440) and S ∗(1720). Using the same data we studied the reaction K − p→ K s 0 K s 0 Y ∗ , where f′(1525) was observed with very small background. No higher mass states were observed with appropriate statistical confidence. In particular, σ(ϑ(1700))× Br(ϑ → K K σ(f′(1520)) ⩽ 0.05 (90% c.l.) , which implies that ϑ cannot be interpreted as an s s state.