Search for pair production of the scalar top quark in the electron-muon final state

TL;DR

This paper reports a search for scalar top quark pair production in proton-antiproton collisions, focusing on electron-muon final states, and sets new exclusion limits on their masses based on the data collected.

Contribution

It presents the first search for scalar top quark pair production in the electron-muon channel at the Tevatron, establishing improved exclusion limits on their masses.

Findings

No significant excess observed over the standard model prediction.

Set 95% confidence level exclusion limits on ($M_{\tilde{t}_1}$,$M_{\tilde{\nu}}$) mass plane.

Enhanced constraints on supersymmetric models involving scalar top quarks.

Abstract

We report the result of a search for the pair production of the lightest supersymmetric partner of the top quark ($\tilde{t}_1$) in $p\bar{p}$ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider corresponding to an integrated luminosity of 5.4 fb$^{-1}$. The scalar top quarks are assumed to decay into a $b$ quark, a charged lepton, and a scalar neutrino ($\tilde{\nu}$), and the search is performed in the electron plus muon final state. No significant excess of events above the standard model prediction is detected, and improved exclusion limits at the 95% C.L. are set in the the ($M_{\tilde{t}_1}$,$M_{\tilde{\nu}}$) mass plane.