Anomalous triple gauge couplings in $e^-e^+\to 4j$: Role of polarizations, spin correlations and interference

TL;DR

This paper explores how polarization, spin correlations, and interference effects influence the detection of anomalous triple gauge couplings in four-jet events at an electron-positron collider, providing improved limits on new physics parameters.

Contribution

It introduces a comprehensive analysis including interference effects and polarization techniques to set tighter bounds on anomalous gauge couplings in four-jet final states.

Findings

Full-hadronic channel yields tighter limits than semi-leptonic.

Interference significantly enhances sensitivity to anomalous couplings.

Polarization and spin correlations improve parameter constraints.

Abstract

We investigate the anomalous charged triple gauge boson couplings generated via $SU(2)_l\times U(1)_Y$ gauge invariant dimension-6 operators with final state four jet events in an $e^-e^+$ Collider at $\sqrt{s}=250$~GeV. We consider all the leading order contributions including the contribution from the interference of $W^-W^+$ diagrams with other possible diagrams. The tagging of two $W$ bosons with a pair of jets is done using the jet charge, while the decay products of $W^\prime$s are tagged as \emph{up/down}-type using boosted decision trees to construct polarizations and spin correlations. Marginalized limits on five anomalous couplings are obtained by Markov Chain Monte Carlo analysis using polarizations, spin correlations, and cross~section. We found that the full-hadronic channel provides tighter limits on anomalous couplings than compared to the usually sought-after clean semi-leptonic channel, owing to the large contribution from interference.