Single top production via flavour changing neutral currents in the reactions e(+)e(-) --> (t) over barc/u is searched for in approximately 411 pb(-1) of data collected by ALEPH at centre-of-mass energies in the range between 189 and 202 GeV. In total, 58 events are selected in the data to be compared with 50.3 expected from Standard Model backgrounds. No deviation from the Standard Model expectation is observed. Upper limits at 95% CL on single top production cross sections at roots = 189-202 GeV are derived. A model-dependent limit on the sum of branching ratios BR(t --> Zc) + BR(t --> Zu) < 17% is obtained. (C) 2000 Elsevier Science B.V. All rights reserved.
|Titolo:||Search for single top production in e(+)e(-) collisions at root s=189-202 GeV|
|Data di pubblicazione:||2000|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/S0370-2693(00)01189-8|
|Appare nelle tipologie:||1.1 Articolo in rivista|