| 摘 要： | We have measured the cross section for π+π- production in two-photon collisions using a data sample with an integrated luminosity of 85.9 fb-1 collected with the Belle detector. The f0(980) resonance is observed as a peak in the energy spectrum of the cross section. We also report preliminary results for γγ→π0π0 with two-photon center-of-mass energies ranging from 0.6 to 4.0 GeV, based on a 95 fb-1 data sample. We find at least four resonant structures including a peak from f0(980). In addition, there is evidence for Xc0 production. We also make a preliminary discussion of the angular dependence and cross section ratio of γγ→π+π- and γγ→π0π0.
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