Extracting the Top-Quark Width from Non-Resonant Production

Abstract

In the context of the Standard Model (SM) of particle physics, the relationship between the top-quark mass and width ($\hat{I}{“}_t$) has been precisely calculated. However, the uncertainty from current direct measurements of the width is nearly 50%. A new approach for directly measuring the top-quark width using events away from the resonance peak is presented. By using an orthogonal dataset to traditional top-quark width extractions, this new method may enable significant improvements in the experimental sensitivity in a method combination. Recasting a recent ATLAS differential cross section measurement, we find $\hat{I}{“}_t$ = 1.28 $\pm$ 0.30 GeV (1.33 $\pm$ 0.29 GeV expected), providing the most precise direct measurement of the width.

7 pages, 2 figures