Search for Scalar Top Quark Production in p-pbar Collisions at sqrt(s)=1.96 TeV

TL;DR

This paper reports a search for the supersymmetric scalar top quark in proton-antiproton collisions at 1.96 TeV, setting mass exclusion limits based on data from the CDFII detector at Fermilab.

Contribution

It introduces a novel charm-jet identification algorithm to improve sensitivity in scalar top quark searches at the Tevatron.

Findings

No excess events observed beyond standard model predictions.

Excluded scalar top quark masses below 180 GeV for large mass splittings.

Used 2.6 fb-1 of data from the CDFII detector.

Abstract

We report on a search for the supersymmetric partner of the top quark (scalar top) decaying into a charm quark and a neutralino in p-pbar collisions at sqrt(s)=1.96 TeV. The data sample, collected by the CDFII detector at the Fermilab Tevatron, corresponds to an integrated luminosity of 2.6 fb-1. Candidate events are selected by requiring two or more jets and a large imbalance in the transverse momentum. To enhance the analysis sensitivity, at least one of the jets is required to be identified as originating from a charm quark using an algorithm specifically designed for this analysis. The selected events are in good agreement with standard model predictions. In the case of large mass splitting between the scalar top quark and the neutralino we exclude a scalar top quark mass below 180 GeV at 95% confidence level.