Scalar quark searches in $e^{+} e^{-}$ collisions at $S^{(1/2)}$ = 181-GeV - 184-GeV

Searches for scalar top, scalar bottom and degenerate scalar quarks have been performed with data collected with the ALEPH detector at LEP. The data sample consists of 57 pb^-1 taken at sqrt{s} = 181-184 GeV. No evidence for scalar top, scalar bottom or degenerate scalar quarks was found in the channels tilde{t} --> c chi, tilde{t} --> b l snu, tilde{b} --> b chi, and tilde{q} --> q chi. From the channel tilde{t} --> c chi a limit of 74 GeV/c^2 has been set on the scalar top quark mass, independent of the mixing angle. This limit assumes a mass difference between the stop and the chi in the range 10-40 GeV/c^2. From the channel tilde{t} --> b l snu the mixing-angle-independent scalar top limit is 82 GeV/c^2, assuming m_stop - m_snu > 10 GeV/c^2. From the channel tilde{b} --> b chi a limit of 79 GeV/c^2 has been set on the mass of the supersymmetric partner of the left-handed state of the bottom quark. This limit is valid for m_sbottom - m_chi > 10 GeV/c^2. From the channel tilde{q} --> q chi a limit of 87 GeV/c^2 has been set on the mass of supersymmetric partners of light quarks, assuming five degenerate flavours and the production of both ``left-handed'' and ``right-handed'' squarks. This limit is valid for m_squark - m_chi > 5 GeV/c^2.

Note:

15 pages, 5 figures, submitted to Physics Letters B Report-no: CERN-EP/98-076

electron positron: colliding beams
electron positron: annihilation
squark: search for
squark: top
squark: bottom
squark: decay modes
squark: mass
lower limit
ALEPH
experimental results

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Scalar quark searches in e+e−e^{+} e^{-}e+e− collisions at S(1/2)S^{(1/2)}S(1/2) = 181-GeV - 184-GeV

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Scalar quark searches in $e^{+} e^{-}$ collisions at $S^{(1/2)}$ = 181-GeV - 184-GeV