Formation of Strange Dibaryonic Resonance X(2265) in p + p → K+ + X reaction at Tp = 2.5 and 2.85 GeV

Abstract

Analysis results of DISTO data on pp → pΛK+ at Tp = 2.50 GeV are discussed in comparison with the previously reported X(2265) resonance with MX = 2267 MeV/c² and ΓX = 118 MeV found in the same reaction at 2.85 GeV. The yield at 2.5 GeV is found much less than that at 2.85 GeV (less than 10%). We discuss that this unexpectedly low yield is actually consistent with the nearly vanishing production yield of Λ(1405) in the observed data and this can thus be indicating that Λ(1405) plays an important role as a doorway state for the formation of X(2265).