Probing the weak mixing angle at high energy

Abstract

The weak mixing angle is a probe of the vector-axial coupling structure of electroweak interactions. It has been measured precisely at the $Z$-pole by experiments at the LEP and SLD colliders, but its energy dependence above $M_Z$ remains unconstrained. In this contribution we propose to exploit measurements of Neutral-Current Drell Yan at large invariant dilepton masses at the Large Hadron Collider, to determine the scale dependence of the weak mixing angle in the $\overline{MS}$ renormalisation scheme, $\sin^2 θ_w^{\overline{MS}}(μ)$. Such a measurement can be used to test the Standard Model predictions for the $\overline{MS}$ running at TeV scales, and to set model-independent constraints on new states with electroweak quantum numbers. To this end, we present an implementation of $\sin^2 θ_w^{\overline{MS}}(μ)$ in the POWHEG-BOX Monte Carlo event generator, which we use to explore the potential of future analyses with the LHC Run~3 and High-Luminosity datasets. In particular, the impact of the higher order corrections and of the uncertainties due to the knowledge of parton distribution functions are studied.