High Statistics Measurement of the Cross Sections of γγ→π⁺π^- Production

Abstract

We report on a high statistics measurement of the total and differential\ncross sections of the process gamma gamma -> pi^+ pi^- in the pi^+ pi^-\ninvariant mass range 0.8 GeV/c^2 < W < 1.5 GeV/c^2 with 85.9 fb^{-1} of data\ncollected at sqrt{s}=10.58 GeV and 10.52 GeV with the Belle detector. A clear\nsignal of the f_0(980) resonance is observed in addition to the f_2(1270)\nresonance. An improved 90% confidence level upper limit Br.(eta'(958) -> pi^+\npi^-) < 2.9 x 10^{-3} is obtained for P- and CP-violating decay of the\neta'(958) meson using the most conservative assumption about the interference\nwith the background.\n