(eng)
Search for Scalar Quarks in e+e- Collisions at sqrt(s) up to 209 GeV Searches
for scalar top, scalar bottom and mass-degenerate scalar quarks are performed
in the data collected by the ALEPH detector at LEP, at centre-of-mass energies
up to 209 GeV, corresponding to an integrated luminosity of 675 pb-1. No
evidence for the production of such particles is found in the decay channels
stop->c/u chi, stop->b l snu, sbottom-> b chi, squark-> q chi or in the stop
four-body decay channel stop-> b chi f f' studied for the first time at LEP.
The results of these searches yield improved mass lower limits. In particular,
an absolute lower limit of 63GeV/c2 is obtained for the stop mass, at 95%
confidence level, irrespective of stop lifetime and decay branching ratios.
Comment: 17 pages, 6 figures
