Charged resonances and MDM bound states at a multi-TeV muon collider

A multi-TeV muon collider proves to be very efcient not only for the search for new heavy neutral particles, but also for the discovery of charged bosons of the W′ type. We fnd that, by analyzing the associated production with a Standard Model W, charged resonances can be probed directly up to multi-TeV mass values close to the collision energy, and for very small couplings with the SM fermions, of the order of 10−3 − 10−4 times the SM weak coupling. Additionally, charged bound states of WIMP Minimal Dark Matter, specifcally a Majorana fermionic 5-plet, can be discovered with low statistics by running above the kinematic threshold, at a center-of-mass energy just slightly above the mass of the MDM bound state. This opens up a very interesting possibility for the discovery of WIMPs, complementary to the search for the resonant production of the neutral MDM bound state component, which relies on an on-peak search. For 5-plet MDM, indeed, the proposed search strategy is more efcient than the WIMP searches based on mono-X, missing-mass and disappearing tracks signatures.