# Jet Substructure and Multivariate Analysis Aid in Polarization Study of Boosted, Hadronic $W$ Fatjet at the LHC

**Authors:** Atri Dey, Tousik Samui  
**arXiv:** [2110.02773](https://arxiv.org/abs/2110.02773)  
**Date:** 2021-10-06  
**Summary page:** https://www.summarizepaper.com/en/paper/2110.02773v2/

## Key points

- Investigation of polarization in heavy particles is crucial in collider studies
- Focus on the $W$ boson, which has two distinct polarization states
- Angular distribution of decay products used for analysis
- Study at the 14 TeV LHC to explore polarization of hadronic and boosted $W$ bosons
- Utilization of N-subjettiness and Soft Drop methods to identify subjets within boosted $W$ jets
- Subjets serve as proxies for hadronic decay products of the $W$ boson
- Construction of templates based on variables like $p_\theta$ and $z_j to represent longitudinally and transversely polarized $W$ bosons
- Templates aid in determining fractions of different $W$ polarizations accurately
- Research by Atri Dey and Tousik Samui highlights importance of advanced techniques in particle polarization studies

## Summary

In the field of collider studies, the investigation of polarization in heavy particles is of significant importance. A key focus lies on the massive $W$ boson, which exhibits two distinct polarization states that are typically analyzed through the angular distribution of its decay products. Recently, researchers conducted a study at the 14 TeV LHC to delve into the polarization of both hadronic and boosted $W$ bosons using advanced jet substructure techniques. The study utilized two primary methods - N-subjettiness and Soft Drop - to identify subjets within boosted $W$ jets. These subjets were identified as proxies for the two hadronic decay products of the $W$ boson. By examining variables such as $p_\theta$ and $z_j$, researchers constructed templates representing longitudinally and transversely polarized $W$ bosons. These templates played a crucial role in accurately determining the fractions of different $W$ polarizations within a mixed sample. The research conducted by Atri Dey and Tousik Samui sheds light on the intricate nature of particle polarization studies and emphasizes the significance of utilizing cutting-edge techniques to unravel fundamental properties of heavy particles in collider experiments.