Large angle production of stable particles heavier than the proton and a search for quarks at the CERN intersecting storage rings

Abstract Measurements have been performed on production of particles with mass 1.5 GeV/ c 2 and charge ⩾ 2 3 for θ lab = 62.5° and s = 53 GeV . At p T = 0.7 GeV/ c the relative rate of production of antideuterons to π − is (5 ± 1) × 10 −5 . The deuteron to antideuteron ratio is 3.7 ± 1.2. No new stable particle has been amongst 0.7 × 10 8 charged particles entering our detector.