The $e^+e^- \to \pi^+ \pi^- \pi^+ \pi^-$, $K^+ K^- \pi^+ \pi^-$, and $K^+ K^- K^+ K^-$ cross sections at center-of-mass energies 0.5-GeV - 4.5-GeV measured with initial-state radiation
Phys.Rev.D 71 (2005) 052001, 2005.
SLAC-PEP2. Measurement of the cross sections for 2PI+ 2PI-, K+ K- PI+ PI- and 2K+ 2K- in E+ E- interactions at centre of mass energies from production threshold to 4.5 GeV from data with a photon from the initial state radiation. The data has around 60000 reconstructed events selected from 89 fb-1 data.