Search for Strange Sixquark States in PP → K+X Missing Mass Spectra

A new interest to study the S = -1, B = 2 system has recently been raised due to theoretical predictions coming either from both potential [1] and quark bag model calculations [2] about the existence of narrow exotic states. In particular the NIJMEGEN GROUP [j] predicts in the MIT bag model a large number of 6 quark configurations with strangeness S = 0, -1 or -2. The stability of these states against quark dissociation or two baryon emission increases with the number of strange quarks involved, the optimum case beeing for the S = -2 system (uu dd ss) that could even present a stable di-hyperon state [4]. No experimental evidence for the observation of such S = -2 states has yet been found, but the cross section level reached in these different experimental researches [5] does not rule out their existence.