This document reviews recent results on the search for scalar top and scalar bottom quarks in p{bar p} collisions at (square root)s = 1.96 TeV. The analyses presented are based on data samples with integrated luminosities from 1.0 to 1.9 fb−1 recorded at the Tevatron with the D0 and CDF detectors.

Searches for the supersymmetric partners of top and bottom quarks using data up to 340 pb{sup -1} taken at the Tevatron p{bar p} collider are described. We report on searches for scalar top quarks {tilde t} in the decays {tilde t} {yields} c{tilde {chi}}{sub 1}{sup 0} and {tilde t} {yields} bl{tilde v} and for scalar bottom quarks in the decay {tilde b} {yields} b{tilde {chi}}{sub 1}{sup 0}. No evidence for a signal has been found, but improved exclusion regions have been derived in the framework of a generic minimal supersymmetric extension of the standard model.

We searched for scalar bottom quarks in 156 pb−1 of {bar p}p collisions at √s = 1.96 TeV recorded by the CDF II experiment at the Tevatron. Scalar bottom quarks can be produced from gluino decays in R-parity conserving models of supersymmetry when the mass of the gluino exceeds that of the scalar bottom quark. Then, a scalar bottom quark can decay into a bottom quark and a neutralino. To search for this scenario, we investigated events with large missing transverse energy and at least three jets, two or more of which were identified as containing a secondary vertex from the hadronization of b quarks. We found four candidate events, where 2.6 ± 0.7 are expected from standard model processes, and placed 95% confidence level lower limits on gluino and scalar bottom quark masses of up to 280 and 240 GeV/c2, respectively.

We searched for scalar bottom quarks in 156 pb−1 of {bar p}p collisions at √s = 1.96 TeV recorded by the CDF II experiment at the Tevatron. Scalar bottom quarks can be produced from gluino decays in R-parity conserving models of supersymmetry when the mass of the gluino exceeds that of the scalar bottom quark. Then, a scalar bottom quark can decay into a bottom quark and a neutralino. To search for this scenario, we investigated events with large missing transverse energy and at least three jets, two or more of which were identified as containing a secondary vertex from the hadronization of b quarks. We found four candidate events, where 2.6 ± 0.7 are expected from standard model processes, and placed 95% confidence level lower limits on gluino and scalar bottom quark masses of up to 280 and 240 GeV/c2 , respectively.

A search for direct production of scalar bottom quarks ({bar b}) is performed with 310 pb−1 of data collected by the D0 experiment in p{bar p} collisions at √s = 1.96 TeV at the Fermilab Tevatron Collider. The topology analyzed consists of two b jets and an imbalance in transverse momentum due to undetected neutralinos ({tilde {chi}}1°), with {tilde {chi}}1° assumed to be the lightest supersymmetric particle. They find the data consistent with standard model expectations, and set a 95% C.L. exclusion domain in the (m{sub {tilde b}}, m{sub {tilde {chi}}}) mass plane, improving significantly upon the results from Run I of the Tevatron.

Searches for the lightest scalar top quark {bar t}1 and scalar bottom quark {bar b}1 performed at LEP2 with a center-of-mass energy of up to (square root)s = 209 GeV and at Tevatron using data collected at (square root)s = 1.8 TeV during Run I and at (square root)s = 1.96 TeV during Run II, are discussed. Different possible decay modes were considered and no evidence for any such signal was observed. Exclusion limits were extracted.