Formation of the S = -1 resonance X(2265) in the reaction pp → X+K+ at 2.50 and 2.85 GeV

Analyzing DISTO data of pp -> p Lambda K+ at T-p = 2.50 and 2.85 GeV to populate a previously reported X(2265)-resonance with M-X = 2267MeV/c(2) and Gamma(X) = 118 MeV at 2.85 GeV, we found that the yield of X(2265) at 2.50 GeV is much less than that at 2.85 GeV (less than 10%), though it is expected from a kinematical consideration to be produced as much as 33% of that at 2.85 GeV. The small population of X(2265) at 2.50 GeV is consistent with the very weak production of.(1405) at the same incident energy toward its production threshold, thus indicating that Lambda(1405) plays an important role as a doorway state for the formation of X(2265).