Observation of the process e+e--γγγγ
Vasserman I. B., Golubev V. B., Dolinskii S. I., Druzhinin V. P., Dubrovin M. S., Ivanchenko V. N., Pakhtusova E. V., Peryshkin A. N.,. Serednyakov S. I, Sidorov V. A., Usov Yu. V., Shatunov Yu. M.
The quantum electrodynamic process e+e~ -*γγγγ was studied with the VEPP-2M electron-positron storage ring in the energy interval 2E = 0.5-1.4 GeV. The integrated cross section in the kinematic region of large momentum transfer, angular distribution of photons, energy spectra, and spectra of the effective masses of photon pairs were measured.