Inclusive production of $\Lambda$, $K^0_s$ and exotic narrow resonances for systems $K_s^0 p$, $K_s^0 \Lambda$, $\Lambda p$ from p+propane interactions at 10 GeV/c

TL;DR

This study analyzes proton-propane interactions at 10 GeV/c to identify exotic baryon states through invariant mass spectra of various decay channels, reporting potential pentaquark candidates with significant statistical evidence.

Contribution

It provides new experimental data on $ ext{Lambda}$, $K^0_s$, and exotic resonance production, including evidence for narrow peaks possibly indicating pentaquark states in multiple decay modes.

Findings

Identification of narrow peaks at specific invariant masses with high statistical significance.

Experimental cross sections for $ ext{Lambda}$ and $K^0_s$ production in p+propane collisions.

Observation of potential pentaquark candidates in $ ext{Lambda}K^0_s$, $pK^0_s$, and $ ext{Lambda}p$ spectra.

Abstract

Experimental data from the 2m propane bubble chamber for production of $\Lambda$, $K^0_s$ have been used to search of exotic baryon states, in the $K_s^0 p$, $K_s^0 \Lambda$ and $\Lambda p$ decay mode for the reaction p+propane at 10 GeV/c. The estimation of experimental inclusive cross sections for $\Lambda$ and $K^0_s$ production in the p$^{12}C$ collision is equal to $\sigma_{\Lambda}$= 13.3$\pm$1.7 mb and $\sigma_{K^0_s}$= 3.8$\pm$0.6 mb, respectively. The measured $\Lambda /\pi^+$ ratio from pC reaction is equal to (5.3$\pm0.8)*10^{-2}$. The experimental $\Lambda /\pi^+$ ratio from the pC reaction is approximately two times larger than the $\Lambda /\pi^+$ ratio simulated by FRITIOF model from the pC reaction. The invariant mass spectrum $\Lambda K^0_s$ registered narrow peaks in regions of 1750 and 1795 MeV/$c^2$. The statistical significance of these peaks has been estimated as 5.6 and 3.3 S.D., respectively. These would be candidates for the $N^0$ or the $\Xi^0$ pentaquark states. The $pK^0_s$ invariant mass spectrum shows resonant structures with $M_{K_s^0 p}$=1540, 1613, 1821 MeV/$c^2$. The statistical significance of these peaks have been estimated as 5.5,4.8 and 5.0 s.d., respectively. The invariant mass spectrum S=-1 $\Lambda p$ observed a narrow peaks at 2100, 2175,2285 and 2353 MeV/$c^2$. Their excess above background by the second method is 6.9, 4.9, 3.8 and 2.9 S.D., respectively.