Measuring BR($h \to \tau ^+ \tau ^-$) at the ILC: a full simulation study

TL;DR

This study assesses the precision of measuring the Higgs boson's decay into tau pairs at the ILC using full detector simulation, achieving an estimated accuracy of 3.4% with advanced analysis techniques.

Contribution

It provides a detailed simulation-based evaluation of the Higgs to tau tau branching ratio measurement at the ILC, incorporating realistic detector effects and analysis methods.

Findings

Estimated measurement accuracy of 3.4% for BR(h→τ+τ−)

Utilized full simulation of the ILD detector concept

Applied multivariate analysis techniques for improved precision

Abstract

We evaluate the expected measurement accuracy of the branching ratio of the Standard Model Higgs boson decaying into tau pairs at the ILC with a full simulation of the ILD detector concept. We assume a Higgs mass of 125 GeV, a branching ratio of BR($h \to \tau ^+ \tau ^-$) = 6.32%, a beam polarization of electron (positron) of -0.8(+0.3), and an integrated luminosity of 250 fb$^{-1}$. The Higgs-strahlung process $e^+ e^- \to Zh$ with $Z \to q\overline{q}$ is analyzed. We estimate the measurement accuracy of the branching ratio $\Delta (\sigma \times \mathrm{BR}) / (\sigma \times \mathrm{BR})$ to be 3.4% with using a multivariate analysis technique.