Dark matter production through a non-thermal flavon portal

Abstract

The Froggatt-Nielsen (FN) mechanism provides an attractive way of generating the determined fermion mass hierarchy and quark mixing matrix elements in the Standard Model (SM). Here we extend it by coupling the FN field, the flavon, to a dark sector containing one or more dark matter particles which are produced non-thermally sequentially through flavon production. Non-thermal flavon production occurs efficiently via freeze-in and through field oscillations. We explore this in the regime of high-scale breaking Λ of the global U(1)FN group and at the reheating temperature TR ≪ Λ where the flavon remains out of equilibrium at all times. We identify phenomenologically acceptable regions of TR and the flavon mass where the relic abundance of dark matter and other cosmological constraints are satisfied. In the case of one-component dark matter we find an effective upper limit on the FN charges at high Λ, i.e. $$ {Q}_{\textrm{FN}}^{\textrm{DM}}\le 13 $$ Q FN DM ≤ 13 . In the multi-component dark sector scenario the dark matter can be the heaviest dark particle that can be effectively stable at cosmological timescales, alternatively it can be produced sequentially by decays of the heavier ones. For scenarios where dark decays occur at intermediate timescales, i.e. t ~ 0.1 − 1028 s, we find that existing searches can effectively probe interesting regions of parameter space. These searches include indirect probes on decays such as γ-ray and neutrino telescopes as well as analyses of the Cosmic Microwave Background, as well as constraints on small scale structure formation from the Lyman-α forest. We comment on the future prospects of such probes, place projected sensitivities, and discuss how this scenario could accommodate the cosmological S8 tension.

Cosmology of axion dark matter

“…See also Ref. [263][264][265][266][267] for a discussion of other alternative cosmological scenarios in the context of ALP dark matter.…”

Exploring freeze-out and freeze-in dark matter via effective Froggatt-Nielsen theory

“…with m a > m b . This bound significantly limits the FN symmetry breaking scale v ϕ , especially for m a ≳ O (10) GeV where the constraints from meson decays are irrelevant. Note that the scalar flavon s also contributes to these processes.…”

“…On the other hand, if the mass of the pseudoscalar is O(10) GeV, then the low-energy data provide the most stringent constraints, excluding DM masses below a few TeV. Moreover, as illustrated by the darker green region, the parameter space allowed for m a ∼ O (10) GeV is entirely inside the neutrino fog. Future DM detection experiments with directional sensitivity [62,63] may be able to probe this scenario.…”

“…Our analysis focuses on relatively heavy mediators and the DM mass spectrum compared to some previous analyses where the freeze-out mechanisms [9] and freeze-in mechanisms [10,11] are studied separately through the scalar flavon portal. Flavon theories inherently induce the flavor-changing neutral current (FCNC) at the tree level.…”

FIMP dark matter from flavon portals

“…While this paper was being prepared ref. [24] appeared which has discussed FIMP dark matter in the context of flavon. There it is assumed that the flavon is produced non-thermally via freeze-in and through field oscillations.…”