Search for Scalar Top Admixture in the ttbar Lepton+Jets Channel at D0

TL;DR

This paper reports a search for scalar top quark pairs in the lepton+jets channel using approximately 1 fb^(-1) of data, aiming to distinguish potential signals from standard top quark pair production.

Contribution

It introduces a method to differentiate scalar top quark pair production from top quark pairs based on kinematic differences in the lepton+jets channel.

Findings

Set upper cross section limits for stop pair production at 95% confidence level.

Limits are 7-12 times higher than MSSM expectations for certain mass ranges.

No significant excess observed over the Standard Model background.

Abstract

A search has been performed for scalar top quark pair production in the lepton+jets channel in ~1 fb^(-1) of data. Kinematic differences between the exotic stop-stopbar and the dominant ttbar process are used to separate the two possible contributions. For scalar top quark masses of 145-175 GeV and chargino masses of 105-135 GeV we obtain upper cross section limits at 95% confidence level for stop-stopbar production that are a factor of ~7-12 higher than expected for the Minimal Supersymmetric Standard Model (MSSM).