Study of the top reconstruction in top-partner events at the LHC

TL;DR

This paper investigates the reconstruction of top-partner events in the Littlest Higgs model with T-parity at the LHC, focusing on top quark polarization, jet algorithms, and mass measurement techniques.

Contribution

It demonstrates the reconstruction of the ttbar system, measures the top-partner mass using m_{T2}, and compares jet algorithms to optimize polarization studies.

Findings

Clustering algorithms improve top polarization analysis.

Successful reconstruction of the ttbar system in LHT events.

Effective top-partner mass measurement from m_{T2} distribution.

Abstract

In the Littlest Higgs model with T-parity (LHT), top-partners (T_-) are produced in pairs at the Large Hadron Collider (LHC). Each top-partner decays into a top quark (t) and the lightest T-odd gauge partner A_H. We demonstrate reconstruction of the ttbar system decaying hadronically, and measurement of the top-partner mass from the m_{T2} distribution. A top quark from a T_{-} decay is polarized, and we discuss the effect of this polarization on the decay distributions. Because the events consist of highly collinear jets which occasionally overlap each other, we compare distributions using different jet reconstruction algorithms (Snowmass cone, kt, Cambridge, SISCone). We find clustering algorithms are advantageous for studying top polarization effects.