MEASUREMENTS OF γγ → K_S~0 K_S~0 AND CHARMONIUM PRODUCTION AT BELLE

摘要

We use data samples collected with the Belle detector at the KEKB e~+e~- collider at 397 fb~(-1) integrated luminosity to measure the cross sections and angular distributions of K_S~0 K_S~0 production in two-photon collisions at the center-of-mass energy (W) and angle (θ~*) ranges, 2.4 GeV < W < 4.0 GeV and |cos θ~*| < 0.6. A sin~(-4) θ~* behavior of the cross section in the region 2.4 GeV < W < 4.0 GeV is observed. Signals of χ_(c0) and χ_(c2) are also observed. Furthermore, new resonance Z(3930) is observed in γγ → DD process using data corresponding to 280 fb~(-1) integrated luminosity.