Physics Beyond the Single Top Quark Observation

TL;DR

This paper reports multiple new measurements related to single top quark production, including cross sections, top quark properties, and limits on new physics, based on the same dataset used for the initial observation.

Contribution

It presents new independent measurements of the t-channel, tau final state, top quark width, and limits on flavor-changing neutral currents, expanding understanding of top quark physics.

Findings

Measured the t-channel production mode independently.

Determined the combined cross section in tau lepton final state.

Set upper limits on flavor-changing neutral currents.

Abstract

In March 2009, the DZero Collaboration first observed the electroweak production of single top quarks at 5 sigma significance. We measured the cross section for the combined s-channel and t-channel production modes, and set a lower limit on the CKM matrix element |V_tb|. Since then, we have used the same dataset to measure the t-channel production mode independently, the combined cross section in the hadronically-decaying tau lepton final state, and the width and lifetime of the top quark, and we have set upper limits on contributions from anomalous flavor-changing neutral currents. This paper describes these new measurements, as presented at the 3rd International Workshop on Top Quark Physics, held in Brugge, Belgium, May 31 - June 4, 2010.