Improved W boson mass measurement with the D0 detector

TL;DR

This paper reports an improved measurement of the W boson mass using the D0 detector, incorporating edge electrons to increase data sample size and refine response parameters, leading to a more precise result.

Contribution

The study introduces the use of edge electrons in W boson mass measurement, enhancing data sample and measurement precision compared to previous D0 analyses.

Findings

W boson mass measured as 80.483 +/- 0.084 GeV

14% increase in W sample size from edge electrons

8% overall improvement in measurement precision

Abstract

We have measured the W boson mass using the D0 detector and a data sample of 82 pb^-1 from the Tevatron collider. This measurement used W -> e nu decays, where the electron is close to a boundary of a central electromagnetic calorimeter module. Such 'edge' electrons have not been used in any previous D0 analysis, and represent a 14% increase in the W boson sample size. For these electrons, new response and resolution parameters are determined, and revised backgrounds and underlying event energy flow measurements are made. When the current measurement is combined with previous D0 W boson mass measurements, we obtain M_W = 80.483 +/- 0.084 GeV. The 8% improvement from the previous D0 measurement is primarily due to the improved determination of the response parameters for non-edge electrons using the sample of Z bosons with non-edge and edge electrons.