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 observ...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→ π^0π^0 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→π^oπ^o.展开更多
文摘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→ π^0π^0 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→π^oπ^o.
