a Test of Quantum Electrodynamics at Small Angles Using the PEP-4 Facility.

A test of QED using Bhabha scattering and two -photon annihilation processes has been performed using the PEP-4 facility. This measurement focuses on the polar angle region from 16(DEGREES) to 33(DEGREES) where the PEP-4 Pole Tip Calorimeters (PTCs) select events on the basis of large back-to-back electromagnetic shower energy deposits. The measured angular distributions of the processes e('+)e('-) (--->) e('+)e('-) and e('+)e('-) (--->) (gamma)(gamma) are consistent with radiatively-corrected QED prediction. Attributing possible QED-modifying terms to the existence of hypothetical massive particles, limits involving particle masses and coupling strengths have been determined. Using the standard cutoff parameter notation, (LAMDA)(,+) = 67 GeV, and (LAMDA)(, -) = 53 GeV in the Bhabha sector. For two-photon annihilation, (LAMDA)(,+) = 29 GeV, and (LAMDA)(,-) = 25 GeV.