@article{b28ac4bce86146d8ab305c1b65c24683,
title = "A search for neutral heavy leptons",
abstract = "In e+e- annihilations at SPEAR we have searched for narrow neutral resonances in the eπ and μπ channels for masses between 0.5 GeV/c2 and 1.5 GeV/c2. No evidence for such states has been found. Under standard theoretical assumptions for production cross sections and decay branching ratios of heavy leptons a lower limit of 1.2 GeV/c2 can be set on the mass.",
author = "Meyer, {D. I.} and Nguyen, {H. K.} and Abrams, {G. S.} and Alam, {M. S.} and A. Barbaro-Galtieri and Boyarski, {A. M.} and Dorfan, {J. M.} and R. Ely and Feldman, {G. J.} and J. Feller and A. Fong and B. Gobbi and G. Hanson and Johnson, {A. D.} and Jaros, {J. A.} and Kadyk, {J. A.} and Kwan, {B. P.} and P. Lecomte and D. L{\"u}ke and Madaras, {R. J.} and J. Martin and Miller, {D. H.} and Parker, {S. I.} and Paterson, {J. M.} and Perl, {M. L.} and I. Peruzzi and M. Piccolo and Pun, {T. P.} and P. Rapidis and Ronan, {M. T.} and R. Ross and W. Tanenbaum and Trilling, {G. H.} and T. Trippe and V. Vuillemin and Wiss, {J. E.} and D. Yount",
note = "Funding Information: There has been considerable speculation about the existence of a massive neutral lepton, N, which would couple to the electron in a right-handed doublet as the neutrino does in the left-handed doublet. Since the decay K -+ ~ Ne -+ has not been observed, the mass of such a lepton if it exists must be greater than 0.5 GeV/c 2. One of the main decay modes of such a lepton would be expected to be eeTr~ with a predicted branching ratio \[1\ ] which falls from 80% at M N = 0.5 GeV/c 2 to 10% at M N = 2 GeV/c 2. (There could of course be a similar lepton decaying to/~-+~ and in addition/a-e mixing. Therefore wherever ~ is written in this paper/~ or e is implied.) A possible source of such leptons would be Work supported by the Energy Research and Development Administration. l Permanent address: University of Michigan, Ann Arbor, Michigan. 2 Permanent address: LPNHE, Universit6 Paris VI, Paris, France. 3 Fellow of Deutsche Forschungsgemeinschaft. 4 Permanent address: Laboratori Nazionali di Frascati dell' INFN, Rome, Italy. 5 Swiss National Science Foundation Fellow. 6 University of Illinois, Urbana, Illinois.",
year = "1977",
month = oct,
day = "24",
doi = "10.1016/0370-2693(77)90416-6",
language = "English (US)",
volume = "70",
pages = "469--470",
journal = "Physics Letters B",
issn = "0370-2693",
publisher = "Elsevier B.V.",
number = "4",
}