Measuring Z' couplings at the LHC

TL;DR

This paper investigates the potential to measure and distinguish Z' gauge boson couplings at the LHC using advanced NLO QCD calculations, enabling precise coupling extraction for various models and masses.

Contribution

It introduces a new technique for simulating Z' gauge bosons and extends coupling parametrizations to include parity-violating terms, improving analysis accuracy.

Findings

Four coupling combinations can be reliably extracted.

Precise measurements are feasible at 1.5 TeV with 100 fb^{-1}.

Higher mass Z' requires the SLHC for accurate coupling determination.

Abstract

We study the properties of potential new Z' gauge bosons produced through the Drell-Yan mechanism at the LHC. Our analysis is performed using a fully differential next-to-leading order QCD calculation with spin correlations, interference effects, and experimental acceptances included. We examine the distinguishability of different models and the feasibility of extracting general coupling information with statistical, residual scale, and current parton distribution function error estimates included. We extend a previous parametrization of Z' couplings to include parity-violating coupling combinations, and introduce a convenient technique for simulating new gauge bosons on-peak using the concept of basis models. We illustrate our procedure using several example Z' models. We find that one can extract reliably four combinations of generation-independent quark and lepton couplings in our analysis. For a Z' mass of 1.5 TeV, one can determine coupling information very well assuming 100 fb^{-1} of integrated luminosity, and a precise measurement becomes possible with 1 ab^{-1} at the SLHC. For a 3 TeV mass, a reasonable determination requires the SLHC.