A Novel Technique for Studying the Z Boson Transverse Momentum Distribution at Hadron Colliders

TL;DR

This paper introduces a new method to analyze the Z boson transverse momentum distribution at hadron colliders by decomposing it into orthogonal components, improving measurement precision and reducing systematic uncertainties.

Contribution

The novel technique decomposes the Z boson transverse momentum into orthogonal components, enhancing measurement accuracy and robustness against experimental systematics.

Findings

Transverse component is nearly insensitive to lepton momentum resolution.

Measurement of the transverse component is less affected by systematic uncertainties.

Method improves precision over previous Q_T distribution measurements.

Abstract

We present a novel method for studying the shape of the Z boson transverse momentum distribution, Q_T, at hadron colliders in ppbar/pp -> Z/gamma* -> l^+l^-. The Q_T is decomposed into two orthogonal components; one transverse and the other parallel to the di-lepton thrust axis. We show that the transverse component is almost insensitive to the momentum resolution of the individual leptons and is thus more precisely determined on an event-by-event basis than the Q_T. Furthermore, we demonstrate that a measurement of the distribution of this transverse component is substantially less sensitive to the dominant experimental systematics (resolution unfolding and Q_T dependence of event selection efficiencies) reported in previous measurements of the Q_T distribution.