Long-lived signatures of conversion-driven freeze-out

Fuks, Benjamin Heisig, Jan [UCL] Lessa, Andre No, Jose Miguel Sekmen, Sezen Sengupta, Dipan Zurita, Jose et al.[show all]

We consider a dark matter model where the relic density is set by conversion- driven feeze-out. This mechanism predicts long-lived particles at the LHC requiring small couplings and a relatively small mass splitting in the dark sector. As such it falls somewhat in between the typical targets of currently performed long-lived particle searches either considering extreme mass compressions or very small couplings, but lack their combinations. We study various search strategies covering the whole range of possible decay lengths O(1mm−1m), pointing out blind spots in the experimental search programme and estimating the corresponding potential for improvement.