Catching a New Force by the Tail

TL;DR

This paper demonstrates that the LHC can detect or exclude very heavy new gauge bosons up to 10-20 TeV by analyzing interference effects in dilepton spectra, extending current search capabilities.

Contribution

It introduces a method to use precision spectral shape measurements at the LHC to probe heavier Z' bosons beyond direct production limits.

Findings

LHC can exclude Z' bosons up to 20 TeV with high luminosity.

Interference effects significantly enhance the sensitivity to heavy Z' bosons.

The approach extends the mass reach beyond direct detection capabilities.

Abstract

The Large Hadron Collider (LHC) is sensitive to new heavy gauge bosons that produce narrow peaks in the dilepton invariant mass spectrum up to about $m_{Z'}\sim 5$ TeV. $Z'$s that are too heavy to produce directly can reveal their presence through interference with Standard Model dilepton production. We show that the LHC can significantly extend the mass reach for such $Z'$s by performing precision measurements of the shape of the dilepton invariant mass spectrum. The high luminosity LHC can exclude, with 95$\%$ confidence, new gauge bosons as heavy as $m_{Z'} \sim 10-20$ TeV that couple with gauge coupling strength of $g_{Z'} \sim 1-2$.