Measurement of $\hat{I}›$ Polarization in the $\ddot{I}{€}^{-}p\to K^0\hat{I}›$ Reaction at $p_{\ddot{I}{€}^{-}}=1.33$ GeV/$c$ toward a New $\hat{I}›p$ Scattering Experiment

Abstract

This paper presents high-precision experimental data of the polarization of the $\hat{I}›$ hyperon in the $\ddot{I}{€}^{-}p\to K^0\hat{I}›$ reaction, measured in the angular range $0.6<\cos \hat{I}{¸}_{K0}^{CM}<1.0$ with a fine bin width of $d\cos \hat{I}{¸}_{K0}^{CM}=0.05$. The data were obtained from the J-PARC E40 experiment at the K1.8 beamline in the J-PARC Hadron Experimental Facility. The observed average polarization of $\hat{I}›$ in the range $0.60<\cos \hat{I}{¸}_{K0}^{CM}<0.85$ was $0.932\pm 0.058(\text{stat})\pm 0.028(\text{syst})$, demonstrating the successful extraction of precise polarization observables. This result provides essential experimental input for partial wave analysis (PWA) of dynamical coupled-channel (DCC) models, which aim to uncover the underlying mechanisms of $N^{\ast }$ resonances that emerge in intermediate states of $\ddot{I}€N$ and ${\hat{I}}^{3}N$ interactions. Besides, it indicates the feasibility of a strongly polarized $\hat{I}›$ beam suitable for future $\hat{I}›p$ scattering experiments (e.g., J-PARC E86).

Progress of Theoretical and Experimental Physics (PTEP)