QCD's theta-bar parameter could naturally be of order one; neutron EDM limits pin it below 10⁻¹⁰, a fine-tuning no Standard Model symmetry protects. The Peccei-Quinn axion solution remains undetected after four decades, cornered between domain-wall, quality, and isocurvature problems as haloscopes close the windows (Peccei and Quinn 1977; Lu 2024).
The standard framework has one universe with one shot at its parameters, so a value of 10⁻¹⁰ must be enforced by a mechanism, and the mechanism must produce a new particle. The axion carries the double burden of solving the fine-tuning and supplying dark matter, and the null results press on both jobs at once.
SCT changes the boundary conditions of the question. In an eternal universe of infinite collision cycles (P1, P27, P28), our patch's effective parameters are not single draws from nowhere: the matter that thermalized into our Big Bang carried the processed state of its predecessors (P25), and quantities not protected by symmetry are free to evolve across the cycle sequence. A theta-bar relaxing toward small values over the eternal sequence arrives in our cycle already tiny, with no per-cycle mechanism and no new field required: the fine-tuning dissolves the way improbable configurations always dissolve in frameworks with histories, by having had time. SCT registers this as a framework-level reading, the eternal-cycle premises carrying the explanation, with the cycle-to-cycle relaxation dynamics an acknowledged open derivation.
The companion stance is registered with teeth: SCT predicts no axion, because it predicts no dark matter particle of any species, WIMP, axion, or sterile neutrino, the dark phenomenology being coherence rather than substance (P54). Four decades of axion nulls thus sit on SCT's side of the ledger alongside the WIMP exclusions, two particle hunts converging on the same absence. The eternal-cycle architecture is in Paper 1, From Chaos to Convergent Foundations, with the no-particle framework in Paper 13, From Chaos to Coherent Gravity.
Keystone economy: P1 and P27 supply the history, P25 carries the inheritance, P54 registers the absence. The symmetry nothing enforces was never enforced; it was inherited.
The registered kill is the axion itself: a confirmed detection by ADMX or any haloscope refutes the no-particle prediction outright and solves strong CP conventionally, removing the eternal-cycle reading's motivation. The framework-level half is exposed to theory: a demonstration that cycle-to-cycle dynamics cannot relax theta-bar, that thermalization re-randomizes it each cycle, would leave SCT holding the fine-tuning as nakedly as the Standard Model does.