ISSN:
1434-6052
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract In an experiment at the CERN-SPS charged hyperon beam, we have investigated the inclusive $$\Lambda \bar K^0 $$ and $$\Sigma ^0 \bar K^0 $$ final states formed in Ξ− Be interactions. In the $$\Lambda \bar K^0 $$ channel, we observe a signal at 1826 MeV/c2 which can be identified with the known Ξ(1820) resonance. We determine its mass and width to be:M=1826±4 MeV/c2, Г=12±14 MeV/c2. A moment analysis is consistent with a spin of 3/2 and indicates a negative parity for this spin assignment. Also in the $$\Lambda \bar K^0 $$ channel, we observe a 3.6σ signal with the following parameters:M=1963±5 MeV/c2, Г=25±15 MeV/c2. This state, which we call Ξ(1960), is not observed in the $$\Sigma ^0 \bar K^0 $$ channel, leading to an upper limit on the ratio of partial widths $$\Sigma \bar K/\Lambda \bar K$$ of 2.3 (90% confidence level). A moment analysis of the $$\Lambda \bar K^0 $$ final state indicates a spin of 5/2 or greater in the natural spin-parity series 5/2+, 7/2−, etc.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01566758
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