Enhanced Lambda Lambda Production Near Threshold In The C-12(K-,K+) Reaction

Enhanced production of nn pairs, above levels predicted by a two-step process model, has been observed near threshold (in the mass range 2.23-2.26 GeV/c(2)) in the C-12(K-,K+) reaction at 1.66 GeV/c using a scintillating fiber target. The differential cross section for nn production in the momentum region 0.95 less than or equal to p(kappa+)less than or equal to l 1.3 GeV/c averaged over the range 2.3 degrees less than or equal to theta(kappa+)less than or equal to 14.7 degrees was found to be 7.6 +/- 1.3 +/- 0.9 mu b/sr, and that for the enhancement was found to be approximately 3 mu b/sr. (C) 1998 Elsevier Science B.V. All rights reserved.