Measurement of the Resonant and Non-Resonant Branching Ratios in $\Xi_{c}^{0} \rightarrow \Xi^{0} K^+ K^-$

TL;DR

This paper measures the branching ratios of specific decay modes of the $\\Xi_{c}^{0}$ baryon using a large data sample, providing insights into resonant and non-resonant decay processes with precise relative measurements.

Contribution

It presents the first amplitude analysis of $\\Xi_{c}^{0}$ decays to $\\Xi^{0} K^+ K^-$, quantifying resonant and non-resonant branching fractions relative to a normalization mode.

Findings

Branching ratio for $\\Xi_{c}^{0} \\rightarrow \\Xi^{0} \\phi$ is 0.036 ± 0.004 (stat.) ± 0.002 (syst.)

Branching ratio for $\\Xi_{c}^{0} \\rightarrow \\Xi^{0} K^+ K^-$ is 0.039 ± 0.004 (stat.) ± 0.002 (syst.)

Results indicate minor cusping peaks in the background due to these decays.

Abstract

Using the entire data sample of $980$ $fb^{-1}$ integrated luminosity collected with the Belle detector at the KEKB asymmetric-energy $e^{+}e^{-}$ collider, we present an amplitude analysis measuring the branching fractions of the Cabibbo-allowed, $W$-exchange resonant decay $\Xi_{c}^{0} \rightarrow \Xi^{0} \phi (\to K^+ K^-)$ with a polarized $\phi$ and the non-resonant decay via a direct process $\Xi_{c}^{0} \rightarrow \Xi^{0} K^+ K^-$. We present these measurements, relative to the normalization mode $\Xi^{-}\pi^{+}$, and find branching ratios $\frac{\mathcal{B}(\Xi_{c}^{0} \rightarrow \Xi^{0} \phi (\rightarrow K^{+}K^{-}))}{\mathcal{B}(\Xi_{c}^{0} \rightarrow \Xi^{-} \pi^{+})} = 0.036 \pm 0.004 (stat.) \pm 0.002 (syst.)$ and $\frac{\mathcal{B}(\Xi_{c}^{0} \rightarrow \Xi^{0} K^{+} K^{-})}{\mathcal{B}(\Xi_{c}^{0} \rightarrow \Xi^{-} \pi^{+})} = 0.039 \pm 0.004 (stat.) \pm 0.002 (syst.)$ which suggest that only minor cusping peaks occur in the combinatorial background of $\Omega^{*-} \to \Xi^{0}K^{-}$ due to these $\Xi_{c}^{0}$ decays.