Search for double-Lambda hypernuclei and the H dibaryon in the (K-,K+) reaction on C-12.

The E885 collaboration Yamamoto, K. ; Alburger, D.E. ; Barnes, P.D. ; et al.
Phys.Lett.B 478 (2000) 401-407, 2000.
Inspire Record 528779 DOI 10.17182/hepdata.28030

A search for double- Λ hypernuclei ( 12 ΛΛ Be) and H -dibaryons using the 12 C( 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 12 ΛΛ 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/ c 2 . This upper limit is the most sensitive H search result to date for a tightly bound H .

2 data tables

Upper limit is given.

The production of the H-dibaryon could occur via the (K-, K+) reaction on two protons in a nucleus: K- (PP) --> K+ H-dibaryon. Upper limit is given.