The Neutron Lifetime Puzzle and a Tube Test for Velocity-dependent and Geometry-dependent Contributions

This article presents a conservative phenomenological framework for discussing the free-neutron lifetime discrepancy in terms of possible geometry-dependent transport and storage contributions superposed on a common intrinsic time scale. The purpose is not to replace the standard weak-decay description, but to formulate an experimentally testable discriminator capable of separating predominantly velocity-dependent from configuration-dependent effects in the extraction of the neutron lifetime. As a starting point, a compact intrinsic-scale layer is used to introduce a working reference value τ₀ ≈ 877.77s. On top of this baseline, two effective correction channels are added. The first is a weak transport or alignment term for a straight tube geometry, suppressed in first approximation approximately as 1/v<sup>2</sup>. The second is a configuration-mixing term associated with storage or bottle setups, isotropization, and wall-induced scrambling. This leads to a direct and testable expectation: in one and the same straight decay-tube geometry, measurements across a broad speed interval should show either near constancy or only a weak residual speed dependence, whereas larger deviations would point more naturally to storage-specific mixing effects. The formulation is intentionally moderate. It is not presented as derived from QED, nor as a replacement for the standard theory of beta decay. Instead, it is proposed as an effective test framework written in notation-compatible form with respect to the standard operator language and directed toward a concrete straight-tube experiment.