Study of ππ production in two-photon collisions at Belle

Abstract

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 χc0 production. We also make a preliminary discussion of the angular dependence and cross section ratio of γγ → π+π− and γγ → π0π0.