J. Lys

Antiproton proton annihilations at 1.6-2.2 GeV/c into final states with a K1o meson

Abstract Antiproton proton annihilations into final states containing at least one K1o meson have been studied in a 150 000 picture bubble chamber experiment. The experiment covered six incident antiproton momenta in the range 1.6–2.2 GeV/c. Cross sections at each incident momentum are determined for the more abundantly produced final states, and momentum averaged cross sections are determined for some rarer final states, including K 0 K 0 and K 0 K 0 K + K − . Copious resonance production, including double resonance production, is observed, and percentage contributions of different resonance channels are evaluated. Cross sections and resonance fractions are compared with results of other experiments at antiproton momenta in the range 0.7–3.7 GeV/c.

Rho-omega interference in pp → 4π at 1.6 – 2.2 GeV/c☆

Abstract The π + π − mass spectrum from over 3000 events of the reaction pp→ π + π + π − π − at 1.63–2.20 GeV/ c shows evidence for ρ−ω interference. If we allow for ρ-background interference the evidence is weak in our total data, but is strong when we make a particular cut on the momentum transfer, from the proton or antiproton to the π + π − . A fit to the data with this cut gives a lower limit on the branching ratio ω → π + π − to ω → π + π − π o of 1.9% (95% confidence level).