LHC-friendly minimal freeze-in models

Abstract

We propose simple freeze-in models where the observed dark matter abundance is explained via the decay of an electrically charged and/or coloured parent particle into Feebly Interacting Massive Particles (FIMP). The parent particle is long-lived and yields a 1 The HL-LHC is expected to produce ∼ 10 8 Higgs bosons. Typical freeze-in values for yχ lie in the O(10 −13 − 10 −7 ) range, would yield less than 10 −4 DM events at the HL-LHC in our scenario.2 Since, as we will see later on, the DM production at the LHC will occur via the Y Y final state, fermions will have slightly larger production cross-sections than scalars.3 See Ref.[57] for an exception to this, mostly focused on χ being a fermion (a gravitino in Gauge-Mediated Supersymmetry Breaking scenarios) and Y being a scalar lepton (a right-handed stau), but also considering the case of a scalar χ and a fermionic, right-handed Y .

Probing dark matter freeze-in with long-lived particle signatures: MATHUSLA, HL-LHC and FCC-hh

“…We note that ATLAS can reconstruct tracks as short as ∼ 12 cm, while for the CMS tracker the minimum reconstructed track length is ∼ 25 − 30 cm (see e.g. the discussion in [31,80]). As a result, the ATLAS search can constrain smaller lifetimes than the CMS study.…”

“…As previously mentioned, there are several important cosmological constraints on this class of freeze-in DM scenarios (for a discussion of such constraints in similar scenarios, see also [30,31]). The first constraint we need to consider comes from Big Bang Nucleosynthesis (BBN), which accurately explains the measured primordial abundances of light elements in the Universe 13 (see e.g.…”

“…Nevertheless, when freeze-in DM production in the early Universe proceeds via the decay of thermal bath particles [8], the corresponding feeble coupling would make these particles long-lived. Searches for long-lived particles (LLPs) at the LHC and beyond (see [25,26]) have received renewed attention in recent years from the lack of conclusive signals in prompt LHC searches for physics beyond the SM, and provide a promising avenue for probing freeze-in DM scenarios [27][28][29][30][31].…”

“…In this work we analyze the prospects of probing the parameter space of DM freeze-in from the decay of long-lived neutral parent particles at the LHC and future colliders. As opposed to charged/coloured LLPs, which leave tracks in the LHC detectors and could be discovered via searches for heavy stable charged particles (see [31] for an analysis of DM freeze-in LHC signatures in these scenarios), neutral LLPs leave no trace in the ATLAS and CMS detectors until their decay. They constitute an ideal search objective for the proposed MATHUSLA surface detector [26,[32][33][34] and other recent proposals for LLP detectors [35][36][37][38].…”

A long-lived stop with freeze-in and freeze-out dark matter in the hidden sector

“…We note that several works exist in the literature on supersymmetric U (1) extensions of MSSM and their implications on dark matter and collider searches (see, e.g., [29]). Also, several works on signatures of long-lived particles at colliders with freeze-in dark matter have appeared recently [30][31][32][33][34][35] as well as scenarios testing for freeze-in via direct detection [36][37][38][39][40] and indirect detection [41,42]. The analysis of this work is significantly different from these.…”