Searches for Multibaryon States with $\Lambda$ Hyperon Systems in pa Collision at 10 Gev/c

TL;DR

This study analyzes bubble chamber data to search for exotic multibaryon states involving Lambda hyperons, revealing known resonances and potential new signals, with implications for understanding hyperon interactions and multibaryon systems.

Contribution

It provides experimental evidence of multibaryon states and resonance behaviors in Lambda systems at 10 GeV/c, including observations of enhanced mass spectra and discrepancies with existing models.

Findings

Observation of known resonances like Σ*(1385), Λ*(1600), and K*(892).

Enhanced width of Σ*(1385) in p+A reactions compared to PDG data.

Detection of an enhancement in the Λπ− spectrum suggesting a stopped Ξ− in nuclei.

Abstract

Experimental data as a stereo photographs from the 2m propane bubble chamber LHE, JINR have been analyzed for exotic multibaryon metastable and stable states searches. A number of peculiarities were found in the effective mass spectra of: 1)$\Lambda \pi^{\pm}$,$\Lambda \pi^+ \pi^-$, $\Lambda p$, $\Lambda p p$, $\Lambda \pi p$,$\Lambda \Lambda $ and $\Lambda K^0_S$ subsystems. The observed well known $\Sigma^{*+}$(1385),$\Lambda ^*(1600)$ and $K^{*\pm}$(892)resonances are good tests for this method. The width of $\Sigma^{*-}(1385)$ for p+A reaction is two time larger than that presented in PDG. The $\Lambda \pi^-$ spectrum observed enhancement in mass range of 1345 MeV/$c^2$ which interpreted as a stopped in nucleus $\Xi^-$. The cross section of stopped $\Xi^-$ production is $\approx$ 8 times larger than obtained by fritiof model with same experimental conditions.