Speaker
Description
The electron Yukawa coupling has not yet been directly tested at the strength predicted by the Standard Model. An electron–positron collider operating at the Higgs pole can probe this coupling through resonant s-channel Higgs production, although the tiny signal rate and large continuum backgrounds make the measurement exceptionally challenging.
We investigate e⁺e⁻ → H → gg in a conditional CEPC scenario with 10 ab⁻¹ and oppositely directed transverse polarizations of 70% for both beams. Events are processed using a CEPC Delphes-based fast detector simulation with a gluon-tagging response informed by CEPC full-simulation studies. An event-level Particle Transformer is combined with a two-dimensional binned likelihood fit to the classifier score and event azimuthal angle.
With the CEPC full-simulation-informed tagging response, the statistical-only fit gives an expected local significance of 0.2 sigma against the e⁺e⁻ → q q̄ background. A separate configuration adopting the idealized tagging assumptions used by d’Enterria and collaborators in their FCC-ee study reaches 4.5 sigma.
