Spin Correlation Effects in Top Quark Pair Production

TL;DR

This paper investigates how spin correlations in top quark pair production at the LHC depend on gluon helicities, revealing new decay correlation patterns and proposing a novel method for their detection.

Contribution

It provides a detailed analysis of spin correlation effects in top quark pairs at the LHC, highlighting the role of gluon helicities and suggesting a new approach to observe these correlations.

Findings

High-energy gluon fusion dominated by unlike helicities shows specific spin correlations.

Low-energy gluon fusion dominated by like helicities induces strong azimuthal decay correlations.

A new method for detecting spin correlations in top quark pairs at the LHC is proposed.

Abstract

An analysis of the spin correlation effects in top quark pair production at hadron colliders is presented with special emphasis for the Large Hadron Collider (LHC). At the LHC top quark pair production is dominated by gluon-gluon fusion. For gluon-gluon fusion at high energies the production is dominated by unlike helicity gluon fusion which has the same spin correlations as quark-antiquark annihilation. At low energies the production is dominated by like helicity gluon fusion which imparts very strong azimuthal correlations on the di-lepton decay products in top quark pair decay. This production process is studied in detail and this suggest a new way to look for spin correlations in top quark pair production at the LHC.