Speaker
Description
We present a phenomenological study of the Higgs radiative decay to a fermion pair. We include the chirality-flipping diagrams via the Yukawa couplings at the order $\mathcal{O}(y_f^2 \alpha)$, the chirality-conserving contributions via the top-quark loops of the order $\mathcal{O}(y_t^2 \alpha^3)$, and the electroweak loops at the order $\mathcal{O}(\alpha^4)$. All the leptonic radiative decays are potentially observable at the LHC Run 2 or the HL-LHC. The lepton pairs that come from virtual photon conversions are highly boosted and tend to merge into clusters, which may require special treatments for identification. We also study the process $h \to c\bar c \gamma$ and evaluate the observability at the LHC. We find it potentially comparable to the other related studies and better than the $h \to J/\psi\ \gamma$ channel in constraining the charm-Yukawa coupling.
