Observable detail · SM
Strong-CP \(\bar\theta_{QCD}\) (conformal-wall)
| Prediction / mechanism | \(\bar\theta_{QCD} \to 0\) structurally under the conformal-wall theorem; consistent with neutron-EDM bound \(|\bar\theta| \lesssim 10^{-10}\). |
|---|---|
| Measured | Neutron EDM bound \(|\bar\theta| \lesssim 10^{-10}\) (n2EDM 2020). |
| Residual / status | OPEN — mechanism stated; numerical bound below current EDM limit not yet computed |
| Status | OPEN |
| Source paper | DCT-SM-01 |
Mechanism
Conformal-wall protects \(\theta_{QCD}\) at the boundary; the axial \(U(1)\) current acquires a topological boundary condition.
Derivation
The derivation chain follows the cluster paper DCT-SM-01 and reduces to the canonical DCT constants (\(P_0 = 0.851\), \(\omega_0 = 50{,}037\), \(c_{BD} = 138{,}189\), master identity \(2\omega_0 + 3 = c_{BD} \cdot P_0^2 = 100{,}077\)). See the cluster paper for the full multi-line derivation.
Methodology
| Domain | Standard Model number suite (SM) |
|---|---|
| Input data source | See "References" below for the canonical public-archive citation. |
| Measurement procedure | The measured value used here is the most recent peer-reviewed central value plus 1σ uncertainty from the cited reference. |
| Acceptance threshold | HIT: residual within 1σ of measurement. SOFT: directional agreement within bracketing range. OPEN: untested or unresolved. |
| Falsification threshold | MISS: prediction excluded at ≥3σ by the canonical measurement under the corpus-canonical (constant-\(P_0\)) treatment. |
| Current status | See verdict pill above. |
Python verification
Verification script: particle_physics_tests.py. Run with python3 particle_physics_tests.py to reproduce the canonical DCT result against the public-archive measurement source listed below.
Cross-references
Related observables: conformal-wall-theorem.
Aggregate views: /predictions/ · /scorecard/ · /empirical/ · /outstanding-problems/.
Audit notes
This sub-page is part of the post-build-out of the observable archive (see the observable index). Verdict reflects the corpus-canonical (constant-\(P_0\)) treatment. The cluster-paper deep-link above (DCT-SM-01) is the canonical source of the derivation chain.
References
- Abel et al. 2020 — n2EDM
- Source paper: DCT-SM-01
Back to all observables or the predictions table.