Evaluation of measurement accuracy of h → τ+ τ- branching ratio at the ILC with √s = 250 GeV and 500 GeV

الأصل · EN

We evaluate the measurement accuracy of the branching ratio of h → τ+ τ- at √s = 250 GeV and 500 GeV at the ILC with the ILD detector simulation. For the √s = 250 GeV, we assume the Higgs mass of Mₕ = 120 GeV, branching ratio of Br(h → τ+ τ-) = 8.0 %, beam polarization of P(e-, e+) = (-0.8, +0.3), and integrated luminosity of ∫ L dt = 250 fb ⁻¹. The Higgs-strahlung process e+ e- → Zh with Z → e+ e-, Z → μ+ μ-, Z → qq mode are analyzed. The measurement accuracy is calculated to be Δ(σ· Br) / (σ· Br) = 3.5 %. The scaled result to Mₕ = 125 GeV is estimated to be 4.2 %. For the √s = 500 GeV, we assume the Higgs mass of Mₕ = 125 GeV, branching ratio of Br(h → τ+ τ-) = 6.32 %, beam polarization of P(e-, e+) = (-0.8, +0.3), and integrated luminosity of ∫ L dt = 500 fb ⁻¹. The Higgs-strahlung process e+ e- → Zh with Z → qq mode and WW-fusion process e+ e- → νₑ νₑ h are analyzed. The measurement accuracy is calculated to be Δ(σ· Br) / (σ· Br) = 5.7 % for Higgs-strahlung with Z → qq and 7.5 % for WW-fusion.