Illuminating Degenerate Dark Sector of Inert Doublet Model at Muon Collider

The Inert scalar Doublet Model (IDM) presents a simple yet elegant framework for a scalar dark sector where the lightest mode functions as a viable dark matter candidate under a $\mathbb{Z}_2$ symmetry. With TeV-scale particles accessible to the Large Hadron Collider (LHC) or future colliders, probing different dark matter scenarios within IDM provides an exciting opportunity. While the Higgs portal dark matter scenario is extensively well-studied at the LHC, probing the degenerate scalar dark sector presents some unique challenges, not only in detecting excessively soft decay products and the tiny production cross-section expected at the higher masses. The present study explores the potential of a forward muon facility at a future muon collider to uncover this elusive degenerate dark sector.