Studies of $\gamma\gamma\to\Lambda\bar{\Lambda},\Sigma^0\bar{\Sigma^0}$ production at Belle

TL;DR

This paper reports measurements of hyperon pair production in two-photon collisions at Belle, observing resonance contributions and providing data to test quantum chromodynamics models.

Contribution

First measurement of hyperon pair production cross sections in the 2-4 GeV range at Belle, including resonance contributions and two-photon width times branching ratios of η_c(1S).

Findings

Observation of intermediate η_c(1S) resonance.

Measured two-photon widths times branching ratios.

Data to test QCD models of hyperon production.

Abstract

Cross sections for hyperon pair production from two-photon collisions, $\gamma\gamma\to\Lambda\bar{\Lambda},\Sigma^0\bar{\Sigma^0}$, are measured in the 2-4 GeV energy region at Belle, using 464 fb$^{-1}$ of data. A contribution from the intermediate resonance $\eta_c(1S)$ is observed, and the products of the two-photon width of the $\eta_c(1S)$ and its branching ratios to $\Lambda\bar{\Lambda}$ and $\Sigma^0\bar{\Sigma^0}$ are measured. The results will help test QCD models.