Boosting New Physics Searches in $t\bar{t}Z$ and $tZj$ Production with Angular Moments

TL;DR

This paper introduces angular moments as powerful observables for probing new physics in $t\bar{t}Z$ and $tZj$ production at the LHC, demonstrating their effectiveness in revealing effects beyond the Standard Model, especially in CP-odd sectors.

Contribution

It derives angular moments at NLO in QCD for $t\bar{t}Z$ and $tZj$ processes and shows their potential to detect new physics effects, including CP-odd operators, at the LHC.

Findings

Angular moments effectively probe BSM effects in top-associated Z production.

These observables reveal blind directions to CP-odd operators.

Significant sensitivity to new physics at 14 TeV LHC with 3 ab$^{-1}$ data.

Abstract

The angular moments for the $Z$ boson can be used as analyzers for the underlying production dynamics for the $t\bar t Z$ and $t Zj$ processes. In this manuscript, we derive these angular moments at leading and next-to-leading order in QCD at the LHC. We show that these observables work as efficient probes to beyond the Standard Model effects, considering the Standard Model Effective Field theory framework. Remarkably, we observe that these probes unveil blind directions to CP-odd operators, providing sizable new physics sensitivity at the 14 TeV LHC with 3 ab$^{-1}$ of data.