Search for Leptoquarks and FCNC in e(+)(e)(-) annihilations root s = 183 GeV

A search fur 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 134GcV/c(2) to 171GeV/c(2) for electromagnetic type couplings) and couplings of the leptoquark rates. A search for top-charm flavour changing neutral currents (e(+)e(-) --> (t) over bar 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). (C) 1999 Elsevier Science B.V. All rights reserved. RI De Angelis, Alessandro/B-5372-2009; Gonzalez Caballero, Isidro/E-7354-2010; Krammer, Manfred/A-6508-2010; Muresan, Raluca-Anca/C-3725-2011; Katsanevas, Stavros/A-4297-2011; Peralta, Luis/C-8369-2011; Ruiz, Alberto/E-4473-2011; Marti-Garcia, Salvador/F-3085-2011; Verzi, Valerio/B-1149-2012; branchini, paolo/A-4857-2011; Shellard, Ronald/G-4825-2012; Petrolini, Alessandro/H-3782-2011; Fruhwirth, Rudolf/H-2529-2012; Monge, Maria Roberta/G-9127-2012