L1 Paper 10 Absence of Tree Level Flavor Changing Neutral Currents

This paper establishes that the absence of tree-level flavor-changing neutral currents is not a contingent dynamical feature or an imposed symmetry condition, but a structural consequence of admissibility, standing preservation, and chiral consistency within a local skin. The analysis proceeds by elimination, showing that any admissible interaction structure permitting such currents at tree level necessarily violates identity persistence, collapses equivalence classes required for standing, or relies on illicit scope transport to maintain consistency. Flavor-changing neutral processes are classified as representational artifacts that can arise only through higher-order or mediated descriptions, not as admissible primitive interactions. Allowing them at tree level is shown to destroy compositional stability by conflating distinguishable interaction channels that must remain separated for standing to be conserved. The paper introduces no new primitives and provides no mechanisms or calculations. Its role is boundary-setting: it clarifies why the exclusion of tree-level flavor-changing neutral currents is structurally forced in any admissible local representation, rather than being an empirical coincidence or model-specific assumption.