Higher-order QED corrections to W-boson mass determination at hadron colliders

Abstract

The impact of higher-order final-state photonic corrections on the precise determination of the W-boson mass at the Tevatron and LHC colliders is evaluated. In the presence of realistic selection criteria, the shift in the W mass from a fit to the transverse mass distribution is found to be about 10 MeV in the $W \to μν$ channel and almost negligible in the $W \to e ν$ channel. The calculation, which is implemented in a Monte Carlo event generator for data analysis, can contribute to reduce the uncertainty associated to the W mass measurement at future hadron collider experiments.

Figures (2)

• Figure 1: The transverse mass distribution without lepton identification criteria and detector resolutions (solid histogram), with lepton identification criteria (markers) and with detector resolutions (shaded histogram), in the $W \to e \nu$ channel at $\sqrt{s} = 2$ TeV. Arrows indicate the considered fit region.
• Figure 2: The $\Delta\chi^2 = \chi^2 - \chi^2_{min}$ distributions from a fit to the $M_T$ distribution, including ${\cal O}(\alpha)$ QED corrections (left) and higher-order QED corrections (right), as a function of the $W$ mass shift, at $\sqrt{s} = 2$ TeV. The results for the $W \to e \nu$ and $W \to \mu \nu$ channels are shown.