# ISR effects on loop corrections of a top pair-production at the ILC

## TL;DR

This paper provides precise predictions for top quark pair-production cross-sections at the ILC, including electroweak and initial-state photon emission effects, with detailed two-loop correction analysis.

## Contribution

It introduces a comprehensive calculation of electroweak and initial-state photon effects, including two-loop corrections, for top pair-production at the ILC, enhancing prediction accuracy.

## Key findings

- Weak corrections increase the cross-section by about 4% at 500 GeV.
- Two-loop diagrams contribute less than 0.11% correction.
- Running coupling effects are also analyzed.

## Abstract

Precise predictions for an $e^+e^-\rightarrow t\bar{t}$ cross-section are presented in the energy region from 400 GeV to 800 GeV. Cross-sections are estimated including the beam-polarization effects with full $\mathcal{O}(\alpha)$, and also with the effects of the initial-state photon emission. A radiator technique is used for the initial-state photon emission up to two-loop orders. In this investigation, a weak correction is defined as the full electroweak corrections without the initial-state photonic corrections. As a result, it is determined that the total cross-section of a top quark pair-production receives the weak corrections of $+4\%$ over the trivial initial state corrections at a center of mass energy of 500 GeV. Among the initial state contributions, a contribution from two-loop diagrams gives less than $0.11\%$ correction over the one-loop ones at the center of mass energies of from $400$ GeV to $800$ GeV. In addition, the effect of a running coupling constant is also discussed.