Speaker
Dr
Hideyuki Nakazawa
(National Central University (JP))
Description
We report QCD studies of pseudoscalar meson pair production in two-photon collisions at the Belle experiment. Differential cross sections have been measured for $\pi^+ \pi^-$, $\pi^0 \pi^0$, $K^+ K^-$, $K_S K_S$, $\eta \pi^0$ and $\eta \eta$ final states. Their $W$ dependence and angular distributions are compared with perturbative and non-perturbative QCD predictions at $(2.4-3.1)\ {\rm GeV} < W < (3.3-4.1)\ {\rm GeV}$, where $W$ is the invariant mass of the two-photon system. Existing predictions fail systematically to describe our measurements.
Primary author
Dr
Hideyuki Nakazawa
(National Central University (JP))
