Recoil-free azimuthal angle for precision boson-jet correlation

TL;DR

This paper introduces a recoil-free azimuthal angle for boson-jet correlation measurements, achieving high theoretical accuracy and robustness against background, enabling more precise experimental studies in high-energy collisions.

Contribution

It develops a recoil-free axis for azimuthal angle measurement, enhancing precision and background robustness, with inclusion of full jet dynamics and gluon polarization effects.

Findings

Achieved next-to-next-to-leading logarithmic accuracy.

Observable remains stable using charged particle tracks.

Identified contributions from linearly-polarized gluons.

Abstract

The azimuthal decorrelation between a vector boson and a jet is an essential hard probe in high energy proton-proton and heavy-ion collisions. We overcome intrinsic limitations of previous studies by using a recoil-free axis, achieving unprecedented next-to-next-to-leading logarithmic accuracy with small nonperturbative corrections. This choice of axis also makes the observable robust in the presence of a large background. Furthermore, the azimuthal angle distribution is minimally changed when determined using only charged particle tracks, which offer superior angular resolution for precise measurements. Our effective field theory includes full jet dynamics, and we find contributions from linearly-polarized gluon transverse momentum distributions in the initial and final state.