M. Artuso et al., MEASUREMENT OF THE CROSS-SECTION FOR GAMMA-GAMMA -] P(P)OVER-BAR, Physical review. D. Particles and fields, 50(9), 1994, pp. 5484-5490
A measurement of the cross section for gamma gamma --> p ($) over bar
p is performed at two-photon center-of-mass energies between 2.00 and
3.25 GeV. These results are obtained using e(+)e(-) --> e(+)e(-)p ($)
over bar p events selected from 1.31 fb(-1) of data taken with the CLE
O II detector. The measured cross section is in reasonable agreement w
ith previous measurements and is in excellent agreement with recent ca
lculations based on a diquark model. However, leading order QCD calcul
ations performed using the Brodsky-Lepage formalism are well below the
measured cross section.