Multi-messenger FIMP
摘要
We propose a multi-messenger frontier probe of non-thermal or freeze-in massive particle (FIMP) dark matter (DM) by considering an effective field theory (EFT) setup. Assuming leptophilic operators connecting DM with the standard model (SM) bath, we consider DM mass (mDM) and the reheat temperature of the Universe (Trh) in a regime which prevents DM-SM thermalisation. Low Trh allows sizeable DM-SM interactions even for non-thermal DM allowing the latter to be probed at direct, indirect detection frontiers as well as future electron-positron and muon colliders. An extended reheating period governed by monomial inflaton potential after its slow-roll phase not only generates the required abundance of non-thermal DM via ultraviolet (UV) freeze-in but also brings the scale-invariant primordial gravitational waves (GW) within reach of near future experiments across a wide range of frequencies. While particle physics experiments can probe Trh ∼ 𝒪(10) GeV and FIMP DM with mass mDM ~ 𝒪(1) TeV, future GW detectors are sensitive to a much wider parameter space.