A search for double-Λ hypernuclei ((ΛΛ)/12Be) and H-dibaryons using the 12C(K-, K+) reaction was performed at the BNL-AGS using a high-intensity 1.8 GeV/c K- beam. A missing-mass analysis below the end point of the quasi-free Ξ- production was used to investigate these S = -2 systems. The upper limit obtained for the forward-angle cross section of (ΛΛ)/12 Be production is 6 to 10 nb/sr. This is the first search for the direct production of double-Λ hypernuclei to reach the sensitivity required to observe the signal predicted by theoretical calculations. For the H-production cross section, we have obtained an upper limit in the range of a few nb/sr to 10 nb/sr for the H mass below 2100 MeV/c2. This upper limit is the most sensitive H search result to date for a tightly bound H. (C) 2000 Published by Elsevier Science B.V.
|Number of pages
|Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
|Published - 2000 Apr 13