Study of pair production in single-tag two-photon collisions

シングルタグ2光子衝突における対生成についてのスタディ

増田 正孝*; 谷田 聖   ; Belle Collaboration*; 他185名*

Masuda, Masataka*; Tanida, Kiyoshi; Belle Collaboration*; 185 of others*

We report a measurement of the cross section for pair production in single-tag two-photon collisions, , for up to 30 GeV, where is the negative of the invariant mass squared of the tagged photon. The measurement covers the kinematic range 1.0 GeV 2.6 GeV and for the total energy and kaon scattering angle, respectively, in the center-of-mass system. These results are based on a data sample of 759 fb collected with the Belle detector at the KEKB asymmetric-energy collider. For the first time, the transition form factor of the 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 and mesons are measured as a function of .