The authors have performed a search for the scalar bottom quark ({tilde b}{sub 1}) from gluino ({tilde g}) decays in an R-parity conserving SUSY scenario with m{sub {tilde g}}> m{sub {tilde b}{sub 1}}, by investigating a final state of large missing transverse energy, with three or more jets, and some of them from the hadronization of b-quarks. A data sample of 156 pb{sup -1} collected by the Collider Detector at Fermilab at a center-of-mass energy of {radical}s = 1.96 TeV was used. For the final selection, jets containing secondary displaced vertices were required. This analysis has been performed ''blind'', in that the inspection of the signal region was only made after the Standard Model prediction was finalized. Comparing data with SUSY predictions, they can exclude masses of the gluino and sbottom of up to 280 and 240 GeV/c{sup 2} 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.

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 tt pairs in pp collisions with a center of mass energy $sqrt s$ = 1.8TeV is presented. The analysis looks for tt pairs which decayed through the chain $bar {tt}to Wsp+bWsp-bar btoellsp+bar nu bellsp-nubar b$ where one of the b quarks is explicitly identified. In a sample of 109.4 $pm$ 7.2 pb$sp{-1}$ of data, 6 tags in 4 events are found with an expected background of 1.53 $pm$.33 events. This results in an estimated production cross section of 4.6$sbsp{-3.1}{+4.4}$ pb at $msb{top}$ = 175 GeV/$csp2.$

A search for pair production of third-generation scalar leptoquarks decaying to top quark and $\tau$ lepton pairs is presented using proton-proton collision data at a center-of-mass energy of $\sqrt{s}$ = 8 TeV collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 19.7 fb-1. The search is performed using events that contain an electron or a muon, a hadronically decaying $\tau$ lepton, and two or more jets. The observations are found to be consistent with the standard model predictions. Assuming that all leptoquarks decay to a top quark and a $\tau$ lepton, the existence of pair produced, charge -1/3, third-generation leptoquarks up to a mass of 685 GeV is excluded at 95% confidence level. This result constitutes the first direct limit for leptoquarks decaying into a top quark and a $\tau$ lepton, and may also be applied directly to the pair production of bottom squarks decaying predominantly via the R-parity violating coupling [lambda]' 333.