ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2009, vol. 80, p. -
Measurement of the γγ*→π0 transition form factor
We study the reaction e+e-→e+e-π0 in the single tag mode and measure the differential cross section dσ/dQ2 and the γγ *→π0 transition form factor in the momentum transfer range from 4 to 40GeV2. At Q2>10GeV2 the measured form factor exceeds the asymptotic limit predicted by perturbative QCD. The analysis is based on 442fb-1 of integrated luminosity collected at PEP-II with the BABAR detector at e+e- center-of-mass energies near 10.6 GeV. © 2009 The American Physical Society.