HyperCP sees possible new supersymmetric particle state (March, 2005)


HyperCP has observed the decay Σ+ → proton + μ+ μ-, in what is the rarest baryon decay ever observed. What is more interesting is the fact that the dimuon masses of the three observed events are all the same, at 214.3 MeV, implying that the decay proceeds via a hitherto unknown itermediate state, one consistent with the sgoldstino. See the Fermilab Today article.