Enhanced production of ΛΛ pairs near threshold in (K−,K+)reaction

Enhanced production of ΛΛ pairs are observed very near the threshold (around the mass of 2.24 GeV/c2) beyond prediction of a two-step process model in (K−,K+) reaction at pK−=1.66 GeV/c using the scintillating fiber target. The differential cross section for the ΛΛ production averaged over 2.3°⩽θK+⩽14.7° in the momentum region 0.95⩽pK+⩽1.3 GeV/c was found to be 8.2±1.3 μb/sr, and that for the enhancement approximately 3 μb/sr.