A study of gamma gamma -> Ks Ks production at energies of 2.4-4.0GeV at Belle

TL;DR

This study measures the production cross sections of $K^0_S K^0_S$ in two-photon collisions at energies 2.4-4.0 GeV using Belle data, revealing energy-dependent ratios and observing charmonium signals.

Contribution

First measurement of $K^0_S K^0_S$ cross sections in this energy range and analysis of their ratio to $K^+K^-$, including charmonium state observations.

Findings

Cross sections measured between 2.4 and 4.0 GeV.

The ratio $\sigma(K^0_S K^0_S)/\sigma(K^+K^-)$ decreases with energy.

Signals for $ ext{chi}_{c0}$ and $ ext{chi}_{c2}$ observed.

Abstract

$K^0_SK^0_S$ production in two-photon collisions has been studied using a 397.6 fb$^{-1}$ data sample collected with the Belle detector at the KEKB $e^+e^-$ collider. For the first time the cross sections are measured in the two-photon center-of-mass energy range between 2.4 GeV and 4.0 GeV and angular range $|\cos\theta^*|<0.6$. Combining the results with measurements of $\gamma\gamma\to K^+K^-$ from Belle, we observe that the cross section ratio $\sigma(K^0_SK^0_S)/\sigma(K^+K^-)$ decreases from ~0.13 to ~0.01 with increasing energy. Signals for the $\chi_{c0}$ and $\chi_{c2}$ charmonium states are also observed.