Study of $K_S^0$ pair production in single-tag two-photon collisions

Abstract

We report a measurement of the cross section for $K_S^0$ pair production in single-tag two-photon collisions, $γ^* γ\to K^0_S K^0_S$, for $Q^2$ up to 30 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 GeV < W < 2.6 GeV and $|\cos \hat{I}{¸}^{\ast }|<1.0$ for the total energy and kaon scattering angle, respectively, in the $γ^* γ$ center-of-mass system. These results are based on a data sample of 759 fb${}^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. For the first time, the transition form factor of the $f_2^{\prime }(1525)$ meson is measured separately for the helicity-0, -1, and -2 components and also compared with theoretical calculations. Finally, the partial decay widths of the $\ddot{I}{‡}_{c0}$ and $\ddot{I}{‡}_{c2}$ mesons are measured as a function of $Q^2$.

22 pages, 18 figures, 7 tables, Belle Preprint 2017-25, KEK Preprint 2017-36, Submitted to Physical Review D