- Petradza, M
- Thun, R
- Abrams, G
- Amidei, D
- Baden, AR
- Barklow, T
- Boyarski, A
- Boyer, J
- Burchat, PR
- Burke, DL
- Butler, F
- Dorfan, JM
- Feldman, GJ
- Gidal, G
- Gladney, L
- Gold, MS
- Goldhaber, G
- Haggerty, J
- Jaros, JA
- Kadyk, JA
- Karlen, D
- Lankford, AJ
- Larsen, RR
- LeClaire, BW
- Levi, ME
- Lockyer, NS
- Lüth, V
- Nelson, ME
- Ong, RA
- Perl, ML
- Richter, B
- Riles, K
- Rowson, PC
- Schaad, T
- Schellman, H
- Schmidke, WB
- Sheldon, PD
- Trilling, GH
- Wood, DR
- Yelton, JM
- et al.
We have tested QED to fourth order in the coupling constant in the large-Q2 region by studying four-lepton final states in e+e- interactions with the Mark II detector at the SLAC storage ring PEP (s=29 GeV). All four final-state particles were detected at large angles with respect to the beam axis. For an integrated luminosity of 205 pb-1, we observed ten e+e-e+e-, ten e+e-+-, and one events with opposite-charge pair masses greater than 1 GeV/c2. These events show good agreement with the complete 4 QED calculation. © 1990 The American Physical Society.