# Constraining new resonant physics with top spin polarisation information

## TL;DR

Incorporating top quark polarization data significantly enhances the sensitivity of $t\bar t$ resonance searches, especially in challenging kinematic regions where traditional methods lose effectiveness.

## Contribution

This paper demonstrates that including top polarization information improves the limits in $t\bar t$ resonance searches beyond conventional mass-based analyses.

## Key findings

- Polarization data enhances sensitivity in resonance searches
- Including spin observables improves limit setting
- Analysis applies to semi-leptonic and di-leptonic channels

## Abstract

We provide a comprehensive analysis of the power of including top quark-polarisation information to kinematically challenging $t\bar t$ resonance searches, for which ATLAS and CMS start losing sensitivity. Following the general modeling and analysis strategies pursued by the experiments, we analyse the semi-leptonic and the di-lepton $t\bar t$ channels and show that including polarisation information can lead to large improvements in the limit setting procedures with large data sets. This will allow us to set limits for parameter choices where sensitivity from $m(t\bar t)$ is not sufficient. This highlights the importance of spin observables as part of a more comprehensive set of observables to gain sensitivity to BSM resonance searches.