Two-photon production of pion pairs.

Abstract

We present a new high-statistics measurement of the cross section for the process e+e-e+e-+- at a center-of-mass energy of 29 GeV for invariant pion-pair masses M(+-) between 350 MeV/c2 and 1.6 GeV/c2. We observe the f2(1270) and measure its radiative width to be 3.15±0.04±0.39 keV. We also observe an enhancement in the +- spectrum near 1 GeV. General agreement is found with unitarized models of the +- reaction that include final-state interactions. © 1990 The American Physical Society