The Flavor of QCD Axion Dark Matter

Abstract

We argue that demanding a consistent cosmological history, including the absence of domain walls and strongly interacting relics at the Peccei-Quinn scale, singles out two concrete realizations of hadronic QCD axions as viable dark matter models. These realizations generally feature flavor-violating axion couplings to Standard Model quarks that are unsuppressed at low energies. As a consequence, experiments looking for flavor-violating hadronic processes involving the axion can be sensitive probes of QCD axion dark matter models. In particular, we show that the NA62 and KOTO experiments could detect the $K\to \pi +a$ decay for axions consistent with the observed dark matter abundance via the post-inflationary misalignment mechanism.

11 pages, 4 figures

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Cited by in corpus (8)

• Quark flavor violation and axion-like particles from top-quark decays at the LHC
• Searching for heavy neutral leptons coupled to axion-like particles at the LHC far detectors and SHiP
• Classification of three-family flavoured DFSZ axion models that have no domain wall problem
• Imperfect Axion Precludes the Domain Wall Problem
• Using $\Delta N_{\mathrm{eff}}$ to constrain preferred axion model dark matter
• Flavored Peccei-Quinn symmetries in the minimal $\nu$DFSZ model
• Axion Dark Matter Archaeology with Primordial Gravitational Waves
• Echoes in multi-ALP scenarios