Spectral Vacuum Mechanism (SVM) — Part XX SU(3) Truncation Removal: Controlled j_max → ∞ at Fixed (a, V) in the Physical Sector

Abstract Part XX advances the SVM audit line by operationalizing truncation removal in truncated SU(3) Hamiltonian computations. This is a protocol/audit paper demonstrated on a toy Canonical Test Point (CTP) and does not claim production-level 3+1D SU(3) Yang–Mills physics. At fixed lattice spacing a and finite volume V, we define “controlled j_max → ∞” as stability of low-energy observables under a j_max ladder, quantified by (i) a drift/plateau criterion on a specified low-energy window and (ii) the monotone control ε_mix = ∥B∥² / Δ_H (Part XVIII). The framework is modular with respect to Gauss-law enforcement: the μ-penalty layer from Part XIX (H_μ = H + μ·C, with C = Σ_x Σ_{a=1…8} (G_x^a)²) can be used to separate truncation effects (j_max) from non-Gauss leakage (μ). The main deliverable is a certified truncation-removed dataset at fixed (a,V), accompanied by an adequacy table reporting per-observable thresholds j_adequate, tolerances, ε_mix and drift values, and falsifiability status. Falsifiability is explicit: if drift does not decrease over j ∈ [j*, j*+2], the controlled-limit hypothesis is rejected for the given (a,V), observable set, and window. A reference implementation (Generator Spec v0.1) produces the full artifact suite (CSV/JSON + manifest + checksums) on a canonical test point (CTP), providing a reproducible handoff to Part XXI (V → ∞) and Part XXII (a → 0) without claiming continuum or thermodynamic limits within Part XX. Keywords: Spectral Vacuum Mechanism (SVM); SU(3) lattice gauge theory; Hamiltonian truncation; physical sector; Gauss law; penalty method; ε_mix; plateau test; reproducible artifacts; audit protocol. Add: CTP_SU3_V2_R1_artifacts.zip Other works by the author on this topic: [1] Nemirovsky M., Spectral Vacuum Mechanism - Part XIV Spectral Confinement as a Necessary Condition for Quantum Field Theory Confinement Gate-Induced Spectral Localization and Dimensional Constraints, Zenodo. DOI: 10.5281/zenodo.18140235 (2026) [2] Nemirovsky M., Spectral Vacuum Mechanism - Part XV Unification of the mass formula in SVM particles of the Standard Model, Zenodo. DOI: 10.5281/zenodo.18207487 (2026) [3] Nemirovsky M., Spectral Vacuum Mechanism – Part XVI Spectral Confinement under Truncated SU(2) Gauge Embedding: Preservation of the Spectral Confinement Class, Zenodo. DOI: 10.5281/zenodo.18225421 (2026) [4] Nemirovsky M., Spectral Vacuum Mechanism – Part XVII Spectral Confinement under Truncated SU(3) Gauge Embedding: Toward a Constructive QCD‑like Framework, Zenodo. DOI: 10.5281/zenodo.18280887 (2026) [5] Nemirovsky M., Spectral Vacuum Mechanism – Part XVIII Continuum Trajectory and Low-Energy Self-Consistency under SU(3) Truncation, Zenodo. DOI: 10.5281/zenodo.18415826 (2026) [6] Nemirovsky M., Spectral Vacuum Mechanism – Part XIX Gauss-Law Certificates and Audit Artifacts under SU(3) Truncation, Zenodo. DOI: 10.5281/zenodo.18422292