Light-meson spectroscopy in fermilab experiment E690

Summary

During the last Fermilab fixed-target run experiment E690 wrote on tape five billion events in the reaction pp→Xp_fast. The beam momentum was 800 GeV/c, the target liquid hydrogen and p_fast was a-t<0.6 GeV² forward-going proton with momentum greater than 600 GeV/c. The X system was required to have at least one charged track in an approximately 700 mrad forward cone. The diffractive trigger and the high statistics provide an ideal data set with which to search for light-meson states. We present mass plots based on an analysis of 5% of our data in the channels pp→p_slow(X)p_fast, with (X);a) K_SK^±π^±,b) ϕϕ,c) K_SK_S, andd) K⁺ K⁻.