# Polarization of top quark in vector-like quark decay

## TL;DR

This paper investigates how the polarization of top quarks produced in vector-like quark decays can reveal the nature of VLQ interactions with the Standard Model, aiding in understanding their coupling structures.

## Contribution

It provides calculations of spin-analyzing powers for leptons from top quarks in VLQ decays across various scenarios, highlighting their use in distinguishing VLQ coupling types.

## Key findings

- Top polarization effects vary with VLQ coupling structures.
- Spin-analyzing power calculations can differentiate VLQ interaction types.
- Top decay leptons serve as probes for VLQ properties.

## Abstract

Vector-like quarks (VLQs) are attractive extensions to the Standard Model. They mix with the SM quarks and can lead to rich phenomenology. Determination of VLQ's interaction structure with the SM is then an important issue, which can be inferred from the decay products of VLQs, such as top quark. We calculate the spin-analyzing powers for charged leptons from top quark in VLQ decay for various VLQ scenarios. We find that the top polarization effect will be helpful to distinguish different natures of the VLQ couplings with the SM.