- Riles, K
- Perl, ML
- Barklow, T
- Boyarski, A
- Burchat, PR
- Burke, DL
- Dorfan, JM
- Feldman, GJ
- Gladney, L
- Hanson, G
- Hayes, K
- Hollebeek, RJ
- Innes, WR
- Jaros, JA
- Karlen, D
- Klein, SR
- Lankford, AJ
- Larsen, RR
- LeClaire, BW
- Lockyer, NS
- Lüth, V
- Ong, RA
- Richter, B
- Yelton, JM
- Abrams, G
- Amidei, D
- Baden, AR
- Boyer, J
- Butler, F
- Gidal, G
- Gold, MS
- Goldhaber, G
- Golding, L
- Haggerty, J
- Herrup, D
- Juricic, I
- Kadyk, JA
- Levi, ME
- Nelson, ME
- Rowson, PC
- Schellman, H
- Schmidke, WB
- Sheldon, PD
- Trilling, GH
- Wood, DR
- Schaad, T
- et al.
We have searched for a heavy charged lepton with an associated neutrino of nearly the same mass in e+e- annihilation data taken with the Mark II detector at a center-of-mass energy of 29 GeV. In order to suppress contamination from conventional two-photon reactions, this analysis uses a novel, radiative-tagging technique. Requiring the presence of an isolated, energetic photon allows a search for lepton doublets with mass splittings smaller than that previously accessible to experiment. No evidence for such a new lepton doublet has been found, enabling limits to be placed on allowed mass combinations. Mass splittings as low as 250-400 MeV/c2 are excluded for charged-lepton masses between 500 MeV/c2 and 10 GeV/c2. © 1990 The American Physical Society.