The search for and study of the strange multibaryon states in systems with Λ-hyperon and K s 0 -meson in pA collision at momentum of 10 GeV/c

Abstract

Exotic strange multibaryon states have been observed in the effective mass spectra of: Λπ±, Λπ+π−, Λp, Λpp, Λπp, ΛΛ and ΛK 0 s , K 0 s p, K 0 s π± subsystems. The measured Λ/π+ ratio for average multiplicities from the pC reaction is equal to (5.3 ± 0.8) × 10−2, and it is approximately two times larger than the Λ/π+ ratio simulated by the FRITIOF model and than that of experimental pp reactions at the same energy. The observed wellknown resonances Σ*+ (1385) and K*± (892) from PDG are good tests of this method. The mean value of the mass for the Σ*−(1385) resonance is shifted to 1370 MeV/c 2 and the width is two times larger than the same value from PDG. Such kind of behavior for the width and invariant mass of Σ*− (1385) resonance is interpreted as an extensive contribution from stopped Ξ− → Λπ− and medium effect. There is enhancement of the production contribution for all observed hyperons. A few events were registered by hypothesis of light H 0 and heavy H 0, + dihyperons. Dihyperons were observed by weak decay channels: (Σ− p), (Λpπ−), (Λpπ0), and (K − pp).