Characterizing Invisible Electroweak Particles through Single-Photon Processes at High Energy $e^{+}{e}^{-}$ Colliders

Seong Youl Choi, Tao Han, Jan Kalinowski +2

We explore the scenarios where the only accessible new states at the electroweak scale consist of a pair of color-singlet electroweak particles, whose masses are degenerate at the…