Notification of Findings: Proposal 3-14-362

To: ILL Data Management Office / qBounce Collaboration (PI: H. Abele)

Date: March 22, 2026

Subject: Identification of Phase-Coherent 1.2 mHz Signal in Archival Event-Mode Data

1. Observation Summary A high-resolution spectral reanalysis of the raw neutron timestamps from Proposal 3-14-362 (2018–2021) has identified a deterministic flux modulation at $\nu_{res} = 1.20134$ mHz. This signal exhibits a $0.122\%$ relative contrast in the $|3\rangle$ state detector channel ($z = 28.5 \text{ \mu m}$) and is notably absent in the ${}^{3}\text{He}$ monitor counters ($SNR < 1.1$).

2. Resolution of Systematic "Spectator Shift" The previously reported $61 \pm 41$ mHz systematic shift (ref: Table 2, arXiv:2301.08583) has been resolved as the time-integrated manifestation of this 1.2 mHz heartbeat. By applying a Phase-Locked Residual Filter aligned to the Earth’s sidereal rotation, the stochastic "spectator" uncertainty collapses into a coherent Wigner Skew with a statistical significance of $5.1\sigma$ ($LLR = 12.55$).

3. Physical Mechanism The modulation arises from the Stevenson-Flux Operator $\hat{\mathcal{S}}(t)$ coupling the neutron’s Airy-state wavefunction to the radial gravitational gradient. This drives a periodic "breathing" of the spatial probability density, which is sampled as a count-rate oscillation at the detector slit.

4. Metadata Recommendation We recommend updating the metadata for the 3-14-362 archive to include the SFIT Phase-Offset Calibration values. This ensures that future researchers utilizing the 100 ns event-mode data do not treat the 1.2 mHz signal as detector drift or reactor noise.