R. Barate et al., Search for a scalar top almost degenerate with the lightest neutralino e(+)e(-) collisions at root s up to 202 GeV, PHYS LETT B, 488(3-4), 2000, pp. 234-246
Data collected at centre-of-mass energies from 189 GeV to 202 GeV by the AL
EPH detector at LEP corresponding to an integrated luminosity of 411 pb(-1)
, are analysed in a search for the scalar top in the decay channels (t) ove
r tilde --> c/u chi for small mass differences between the stop and the lig
htest neutralino. No evidence for deviations from the Standard Model expect
ation is found and a lower limit of 59 GeV/c(2) is set for the stop mass, i
ndependent of the stop to neutralino mass difference and of the stop lifeti
me. (C) 2000 Elsevier Science B.V. All rights reserved.