Analysis of t tbar H Events at sqrt(s)=14 TeV with H -> WW

TL;DR

This study analyzes the potential to measure the top quark Yukawa coupling via t tbar H production with H -> WW at 14 TeV, using simulated data and event reconstruction to estimate achievable precision.

Contribution

It provides a detailed simulation-based projection of the measurement precision of the top Yukawa coupling at the LHC, considering systematic uncertainties and theoretical improvements.

Findings

Projected 16% precision on top Yukawa coupling with 300 fb^-1

Projected 9% precision with 3000 fb^-1

Theoretical uncertainty reduction improves precision further

Abstract

We study the process pp -> t tbar H at sqrt(s)=14 TeV where H -> WW. We focus on final states that include three or four leptons. Signal and background samples are generated at leading order (LO) and normalized to next-to-leading order (NLO) calculations. We employ the "Snowmass" detector simulation and event reconstruction. Cuts are selected which provide a substantial signal yield while suppressing the main backgrounds. Systematic uncertainties are estimated for the overall normalization of signal and background processes. With no improvement in the current theoretical uncertainties on sigma(t tbar H), we project a precision on a top quark Yukawa coupling of approximately 16% in 300 fb^-1 and 9% in 3000 fb^-1. If the theoretical uncertainties are halved, these improve to 14% and 6%, respectively.