Speaker
Junya Nakamura
(Universität Tübingen)
Description
A method to measure "directly" the trilinear Higgs self-coupling $\lambda$ in a single Higgs production process is proposed. Time-reversal-odd (T-odd) quantities in the process $e^+e^- \to ZH$, $Z \to f\bar{f}$ are computed from the absorptive part of the electroweak one-loop amplitude. They are essentially up-down asymmetries of the final fermion $f$ with respect to the $ZH$ production plane. The T-odd asymmetries directly measure $\lambda$, because the tree-level diagram for a final-state interaction between the $ZH$ contributes linearly to them.
