Independent Common-Domain Decay and the Complete D–T Geometric Event Clock in Constrained Null Geometry

Abstract

This work derives the post-common-domain decay time and the complete deuterium–tritium geometric event clock within Constrained Null Geometry (CNG). The D–T reaction is separated into two dynamically distinct stages. The first is the previously derived fusion-completion interval, during which the non-additive 2|3 separation memory undergoes a finite recurrence and becomes unable to support another complete return. The second begins only after the common five-label domain has formed and describes its rank-changing reconstruction into the alpha-particle and neutron output. The common 5 → 4 + 1 reconstruction removes one normalized tangent direction while preserving the surviving four-label tangent. Norm preservation requires the lost common direction to be transferred into an orthogonal neutron trace direction. The resulting active geometry is a two-dimensional rotation whose shortest projective path is a quarter turn. Using the independently derived alpha-side kinetic scale and the CNG no-new-scale closure, the post-common decay time is obtained as 2.90318919725 × 10^-22 s. This result is derived independently of the preceding fusion-completion time. The two adjacent stages are then combined through additivity of the same D–T centre-of-momentum proper time, yielding a complete geometric event time of 8.78175082842 × 10^-21 s. Only after this clock is fixed is a minimal single-pole lifetime identification applied. It gives a predicted resonance width of 74.95224697 keV. A downstream Bosch–Hale-based diagnostic gives 74.86260477 keV, corresponding to a residual of +0.119742%. The derivation does not use a measured D–T resonance width, lifetime, resonance energy, nuclear radius, scattering length, effective range, or fitted clock factor to determine the geometric times. The construction also produces a distinct phase-sensitive prediction. The post-common stage contributes an incremental energy-phase slope of 4.41072084 × 10^-4 rad/keV, providing an experimental test independent of the stationary resonance-width comparison. The central result is a two-stage parameter-free CNG timing chain: D–T fusion completion → common-domain decay → complete geometric event clock → downstream resonance audit. The work therefore separates the derivation of the reaction clock from its subsequent experimental comparison and provides explicit falsification conditions for both the geometric clock and its observer-level interpretation.