{
  "status": "passed",
  "checks": {
    "authoritative_CODATA_snapshot_identified": true,
    "SI_mass_and_energy_conversions_agree_to_display_rounding": true,
    "positive_physical_reference_far_exceeds_standard_uncertainty": true,
    "model_calibration_distinguished_from_prediction": true
  },
  "source_url": "https://physics.nist.gov/cuu/Constants/Table/allascii.txt",
  "reference": "2022 CODATA adjustment, NIST complete listing",
  "snapshot_file_mtime_utc": "2026-10-12T15:55:43.569165+00:00",
  "retrieval_note": "Individual CGI constant pages returned HTTP 403. The complete NIST table was successfully retrieved directly over HTTPS.",
  "physical_neutron": {
    "mass_kg": "1.67492750056E-27",
    "mass_standard_uncertainty_kg": "8.5E-37",
    "rest_energy_J": "1.50534976514E-10",
    "rest_energy_standard_uncertainty_J": "7.6E-20",
    "rest_energy_MeV": "939.56542194",
    "rest_energy_standard_uncertainty_MeV": "4.8E-7"
  },
  "exact_conversion": {
    "c_m_per_s": "299792458",
    "joules_per_MeV": "1.602176634000000E-13"
  },
  "source_lines": [
    "neutron mass                                                1.674 927 500 56 e-27    0.000 000 000 85 e-27    kg",
    "neutron mass energy equivalent                              1.505 349 765 14 e-10    0.000 000 000 76 e-10    J",
    "neutron mass energy equivalent in MeV                       939.565 421 94           0.000 000 48             MeV"
  ],
  "nonprediction_control": {
    "model_dimensionless_energy": "0.1850169774116653140794142018421553075313568115234375",
    "energy_unit_MeV_required_to_fit_neutron": "5078.26597906987768342682918249440461800100325145298786176284",
    "interpretation": "This unit is computed FROM the measured neutron energy, so agreement would be calibration by construction, not a derivation or independent test. It has NOT been applied to the model inputs."
  },
  "disposition": "The physical neutron rest energy is established here by an authoritative experimental adjustment. The repository model does not independently derive it.",
  "source_hashes": {
    "research/strominger/results/physical-neutron-reference/codata-allascii.txt": "77fb90e66c40db3e6eb16630bc9c88e4c7c8beddbe5e71be406f2f26e3f67e67",
    "research/strominger/results/neutron-source-action-rest-gap.json": "de65118f465d000e3ceb16bc8a62d4a91ffd969765029f404bfb32877f4c4bc5",
    "research/strominger/checkers/check_physical_neutron_rest_energy.py": "28fb214f0f01e81a1140a18c3daadcd1953046f8924b0c0820d8ca5785f625d7"
  }
}