Study of KS0 pair production in single-tag two-photon collisions
Citations Over TimeTop 11% of 2018 papers
Abstract
We report a measurement of the cross section for ${K}_{S}^{0}$ pair production in single-tag two-photon collisions, ${\ensuremath{\gamma}}^{*}\ensuremath{\gamma}\ensuremath{\rightarrow}{K}_{S}^{0}{K}_{S}^{0}$, for ${Q}^{2}$ up to $30\text{ }\text{ }{\mathrm{GeV}}^{2}$, where ${Q}^{2}$ is the negative of the invariant mass squared of the tagged photon. The measurement covers the kinematic range $1.0\text{ }\text{ }\mathrm{GeV}<W<2.6\text{ }\text{ }\mathrm{GeV}$ and $|\mathrm{cos}{\ensuremath{\theta}}^{*}|<1.0$ for the total energy and kaon scattering angle, respectively, in the ${\ensuremath{\gamma}}^{*}\ensuremath{\gamma}$ center-of-mass system. These results are based on a data sample of $759\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected with the Belle detector at the KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. For the first time, the transition form factor of the ${f}_{2}^{\ensuremath{'}}(1525)$ meson is measured separately for the helicity-0, -1, and -2 components and also compared with theoretical calculations. We have derived the cross section for the process for $W<2.6\text{ }\text{ }\mathrm{GeV}$ from 121 signal candidate events. Finally, the ${\ensuremath{\gamma}}^{*}\ensuremath{\gamma}$ partial decay widths of the ${\ensuremath{\chi}}_{c0}$ and ${\ensuremath{\chi}}_{c2}$ mesons are measured as a function of ${Q}^{2}$ based on 10 candidate events in total.