Measurement of the cross-section for the process gamma gamma --> p anti-p at s(ee)**(1/2) = 183-GeV - 189-GeV at LEP.

The OPAL collaboration Abbiendi, G. ; Ainsley, C. ; Akesson, P.F. ; et al.
Eur.Phys.J.C 28 (2003) 45-54, 2003.
Inspire Record 595836 DOI 10.17182/hepdata.48881

The exclusive production of proton-antiproton pairs in the collisions of two quasi-real photons had been studied using data taken at sqrt(s)_ee=183 GeV and 189 GeV with the OPAL detector at LEP. Results are presented for Ppbar invariant masses, W, in the range 2.15 W< <3.95 GeV. The cross-section measurements are compared with previous data and with recent analytic calculations based on the quark-diquark model.

3 data tables

Cross section as a function of the invariant mass of the pbar-p pair.

Cross section for two photon production of the pbar-p pair.

Angular distributions in 3 W ranges.


Measurement of the proton antiproton pair production from two-photon collisions at TRISTAN.

The VENUS collaboration Hamasaki, H. ; Abe, K. ; Amako, K. ; et al.
Phys.Lett.B 407 (1997) 185-192, 1997.
Inspire Record 443677 DOI 10.17182/hepdata.38332

The cross section of the γγ → p p reaction was measured at two-photon center-of-mass energy ( W γγ ) between 2.2 and 3.3 GeV, using the two-photon process at an e + e − collider, TRISTAN. The W γγ dependence of the cross section integrated over a c.m. angular region of | cos θ ∗ | < 0.6 is in good agreement with the previous measurements and the theoreticalv prediction based on diquark model in the high W γγ region.

2 data tables

Numerical values supplied by Hirhoshi Hamasaki.

Angular distributions.