A Measurement of the Decay Asymmetry Parameters in $\Xi_{c}^{0}\to \X^{-}\pi^{+}$

TL;DR

This paper measures the decay asymmetry parameter of the $\\Xi_c^{0}$ particle, providing a result that favors a negative value but with large uncertainties, contributing to understanding of charm baryon decays.

Contribution

The study provides the first measurement of the decay asymmetry parameter for $\\Xi_c^{0} \\to \\Xi^{-} \\pi^{+}$ decay, with results consistent with theoretical expectations but limited by statistical precision.

Findings

Measured the decay asymmetry parameter as approximately -0.56

Result favors a negative asymmetry parameter at 90% confidence level

Measurement is consistent with theoretical models within uncertainties

Abstract

Using the CLEO II detector at the Cornell Electron Storage Ring we have measured the $\Xi_c^{0}$ decay asymmetry parameter in the decay $\Xi_c^{0} \to \Xi^{-} \pi^+$. We find $\alpha_{\Xi_c^{0}} \alpha_{\Xi} = 0.26 \pm 0.18{(stat)}^{+0.05}_{-0.04}{(syst)}$, using the world average value of $\alpha_{\Xi} = -0.456 \pm 0.014$ we obtain $\alpha_{\Xi_c^{0}} = -0.56 \pm 0.39{(stat)}^{+0.10}_{-0.09}{(syst)}$. The physically allowed range of a decay asymmetry parameter is $-1<\alpha<+1$. Our result prefers a negative value: $\alpha_{\Xi_c^{0}}$ is $<0.1$ at the 90% CL. The central value occupies the middle of the theoretically expected range but is not yet precise enough to choose between models.