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

¹ Stefan Meyer Institute for Subatomic Physics, Austrian Academy of Sciences
² Excellence Cluster Universe, Technische Universität München
³ Dipartmento di Fisica Generale "A. Avogadro" and INFN, Torino, Italy
⁴ Department of Physics, University of Tokyo, Tokyo, 113-0033 Japan
⁵ RIKEN Nishina Center, Wako, Saitama, 351-0198 Japan

^a e-mail: ken.suzuki@oeaw.ac.at
^b e-mail: deceased

Published online: 20 March 2014

Abstract

Analysis results of DISTO data on pp → pΛK⁺ at T_p = 2.50 GeV are discussed in comparison with the previously reported X(2265) resonance with M_X = 2267 MeV/c² and Γ_X = 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).