In Search of Lonely Top Quarks at the Tevatron

TL;DR

This paper reevaluates single top-quark production at the Tevatron, proposing new shape-based analysis methods to improve signal detection amidst challenging backgrounds, especially from W-plus-jets.

Contribution

It introduces novel shape variable techniques focusing on correlations and asymmetries to enhance background suppression and provide background modeling checks.

Findings

Shape variables can significantly reduce backgrounds.

Correlation and asymmetry analyses improve signal extraction.

Systematic issues, particularly with W-plus-jets background, remain challenging.

Abstract

Single top-quark production, via weak-interaction processes, is an important test of the standard model, potentially sensitive to new physics. However, it is becoming known that this measurement is much more challenging at the Tevatron than originally expected. We reexamine this process and suggest new methods, using shape variables, that can supplement the methods that have been discussed previously. In particular, by focusing on correlations and asymmetries, we can reduce backgrounds substantially without low acceptance for the signal. Our method also allows for a self-consistency check on the modeling of the backgrounds. However, at the present time, serious systematic problems remain, especially concerning the background from W-plus-jets; these must be studied further by experimentalists and theorists alike.