Study of top quark pair production near threshold at the ILC

TL;DR

This study analyzes top quark pair production near threshold at the ILC, estimating statistical errors on key parameters like Yukawa coupling, mass, and width using simulated data for different energy points and beam polarizations.

Contribution

It provides new estimates of statistical uncertainties for top quark properties at the ILC near threshold energy, based on detailed detector simulations and energy scans.

Findings

Estimated 4.2% error on top Yukawa coupling

16 MeV precision on top quark mass

21 MeV accuracy on top quark width

Abstract

We report on a study of top pair production at the International Linear Collider (ILC) around center of mass energy (E$_{\rm CM}$) = 350 GeV using an ILD detector simulator based on the Detailed Baseline Design (DBD) configuration. Here we will report on a result of 6-Jet final state, $t\ bar{t} \rightarrow bWbW \rightarrow bqqbqq$. A result for the 4-Jet final state, $t\ bar{t} \rightarrow bWbW \rightarrow bqqbl\nu$, which has almost the same statics as that of the 6-Jet final state will be included in the future. For an energy scan of 11 center of mass energy points (340 - 350GeV) and two beam polarization combinations (P($e^+,\ e^-$) = ($\pm$0.3, $\mp$0.8)) with 10 fb$^{-1}$ each, the statistical errors on the top quark Yukawa coupling, its mass and width are estimated. The results are $\delta y_t$ = 4.2%, $\delta m_t$ = 16 MeV in potential subtracted scheme (PS), and $\delta \Gamma_t$ = 21 MeV.