This record is a patch release of the TDE v16. x “octant ladder” mass model, which represents hadron masses on a low-parameter geometric lattice with fixed hardware-like constants: k = 4*pi + 1, alphaᵢnv = 137. 035999084, E1 = alphaᵢnv/4 ≈ 34. 259 MeV, E0 = k*E1 ≈ 464. 770 MeV, E2 = E1/k ≈ 2. 525 MeV. The mass law is M = A*E0 + B*E1 + C*E2 with quantization constraints A, B in 0. 5*Z and C in Z. Forward rules generate (A, B, C) using PDG features (quark content/flavor, Q, J, P, and name-derived excitation labels such as 1S/2S/1P) without using the experimental mass as input. Reverse-lookup is provided only for diagnostics and is not treated as prediction. v16. 5 introduces an additional class-level correction for the charmonium pseudoscalar S-wave ground state eta (c) (1S) within the existing rule system, while keeping all constants unchanged. On the fixed covered-set of N=74 particles (out of 527 entries in the audit table), the patch improves the overall forward-prediction error from MAE 3. 726 MeV (v16. 4) to MAE 3. 563 MeV (v16. 5), with RMSE 4. 444 MeV and MAPE 0. 215%. Coverage remains 74/527 (14. 04%). Specifically, the residual for eta (c) (1S) is reduced from +12. 35 MeV to −0. 28 MeV using only class features (ccbar, J=0, P=−1) and the “1S” label extracted from the particle name. This work is released as a preprint and as an auditable computational artifact (code + tables + reports). It is a hypothesis-driven “coverage-first” program: rules are defined from particle features first, and only then evaluated against PDG reference masses.
Michał Karol Surowiecki (Thu,) studied this question.