Search for Leptoquarks and FCNC in e+e− annihilations at [formula omitted] GeV

• Published in: Physics letters. B 1999, Vol.446 (1), p.62-74
• Main Authors: Abreu, P., Alekseev, G.D., Amaldi, U., Andersson, P., Antilogus, P., Arnoud, Y., Barao, F., Bardin, D.Y., Belokopytov, Yu, Bertini, D., Booth, P.S.L., Borisov, G., Boudinov, E., Bozzo, M., Buran, T., Camacho Rozas, A.J., Chapkin, M., Chaussard, L., Chudoba, J., Cowell, J-H., Crawley, H.B., De Paula, L., Drees, J., Eigen, G., Elsing, M., Engel, J-P., Erzen, B., Feindt, M., Ferrari, P., Ferrer, A., Gamblin, S., Gaspar, C., Gavillet, Ph, Gele, D., Glege, F., Golob, B., Gopal, G., Gouz, Yu, Guy, J., Harris, F.J., Herr, H., Jackson, J.N., Johansson, E.K., Katsanevas, S., Kiiskinen, A., Koratzinos, M., Kubinec, P., Lauhakangas, R., Lepeltier, V., Lippi, I., Lopez-Fernandez, R., Lutz, P., Maio, A., Malychev, V., Marco, R., Mc Kay, R., Mc Nulty, R., Mc Pherson, G., Mirabito, L., Mitaroff, W.A., Moeller, R., Monge, M.R., Moreau, X., Morton, G., Mulders, M., Myklebust, T., Negri, P., Nikolenko, M., Olshevski, A.G., Onofre, A., Palacios, J., Palka, H., Pape, L., Pegoraro, M., Piotto, E., Pozdniakov, V., Regler, M., Resvanis, L.K., Royon, Ch, Ruiz, A., Sannino, M., Schwemling, Ph, Schwickerath, U., Segar, A.M., Smadja, G., Smith, G.R., Stevenson, K., Stugu, B., Szeptycka, M., Tabarelli, T., Terranova, F., Timmermans, J., Tinti, N., Tomaradze, A., Tome, B., Tyapkin, I.A., Van Dam, P., Vilanova, D., Weiser, C., Wilkinson, G.R.
• Format: Article
• Language: English
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/S0370-2693(98)01525-1

A search for events with one jet and at most one isolated lepton used data taken at LEP-2 by the DELPHI detector. These data were accumulated at a center-of-mass energy of 183 GeV and correspond to an integrated luminosity of 47.7 pb −1. Production of single scalar and vector leptoquarks was searched for. Limits at 95% confidence level were derived on the masses (ranging from 134 GeV/c 2 to 171 GeV/c 2 for electromagnetic type couplings) and couplings of the leptoquark states. A search for top-charm flavour changing neutral currents ( e +e −→ t ̄ c or charge conjugate) used the semileptonic decay channel. A limit on the flavour changing cross-section via neutral currents was set at 0.55pb (95% confidence level).