Enhanced production of ΛΛ pairs near threshold in the (K-,K+) reaction on 12C

Enhanced production of Lambda Lambda pairs, above the prediction of a two-step process model, is observed near threshold (around the masses of 2.23 - 2.26 GeV/c(2)) in the C-12(K-,K+) reaction at p(K-) = 1.66 GeV/c using a scintillating fiber target. The differential cross section for the Lambda Lambda production averaged over 2.3 degrees less than or equal to theta(K+) less than or equal to 14.7 degrees in the momentum region 0.95 less than or equal to p(K+) less than or equal to 1.3 GeV/c was found to be 7.6 +/- 1.3 mu b/sr, and that for the enhancement approximately 3 mu b/sr.