A Search for Scalar Bottom Quarks from Gluino Decays in $\bar{p}p$ Collisions at $\sqrt{s}=1.96$ TeV

TL;DR

This paper reports a search for scalar bottom quarks produced from gluino decays in proton-antiproton collisions at 1.96 TeV, setting new mass limits based on observed events and standard model background estimates.

Contribution

First search for scalar bottom quarks from gluino decays in proton-antiproton collisions at Tevatron, establishing new lower mass limits in supersymmetry models.

Findings

Observed 4 candidate events with 2.6±0.7 expected from background.

Placed 95% CL lower limits on gluino mass up to 280 GeV.

Placed 95% CL lower limits on scalar bottom quark mass up to 240 GeV.

Abstract

We searched for scalar bottom quarks in 156 pb$^{-1}$ of {\bf $\bar{p}p$} collisions at {\bf $\sqrt{s}=1.96$} 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 $2.6\pm 0.7$ 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 $240\gevm$, respectively.