Author/Authors :
ALEPH Collaboration، نويسنده , , R. Barate، نويسنده , , D. Buskulic، نويسنده , , D. Decamp، نويسنده , , P. Ghez، نويسنده , , C. Goy، نويسنده , , J.-P. Lees، نويسنده , , A. Lucotte، نويسنده , , M.-N. Minard، نويسنده , , Nief، Francois نويسنده , , B. Pietrzyk، نويسنده , , M.P. Casado، نويسنده , , M. Chmeissani، نويسنده , , P. Comas، نويسنده , , J.M. Crespo، نويسنده , , M. Delfino، نويسنده , , E. Fernandez، نويسنده , , M. Fernandez-Bosman، نويسنده , , Ll. Garrido، نويسنده , , A. Juste، نويسنده , , et al.، نويسنده ,
Abstract :
Searches for scalar top and bottom quarks have been performed with data collected by the ALEPH detector at LEP. The data sample consists of 21.7 pb−1 taken at s = 161, 170, and 5.7 pb−1 taken at s = 130 and 136 GeV . No evidence for scalar top quarks or scalar bottom quarks was found in the channels t → cχ, t → bℓν, and b → bχ. For the channel t → cχ a limit of 67 GeV/c2 has been set on the scalar top quark mass, independent of the mixing angle between the supersymmetric partners of the left and right-handed states of the top quark. This limit assumes a mass difference between the t and the χ of at least 10 GeV/c2. For the channel t → bℓν the mixing-angle independent scalar top limit is 70 GeV/c2, assuming a mass difference between the t and the ν of at least 10 GeV/c2. For the channel b → bχ, a limit of 73 GeV/c2 has been set on the mass of the supersymmetric partner of the left-handed state of the bottom quark. This limit is valid if the mass difference between the b and the χ is at least 10 GeV/c2.
