# LIB2-126 — The separate QED matching step gives the displayed physical muon mass

- class: CLAIM · review_state: PUBLISHED · house_tier: not yet assigned
- labels as printed: math_status NOT_PRINTED · attachment NOT_PRINTED · scorecard tier word none (PDF p.34)
- basis: {"pdf_sha256_prefix": "b64ddcd9e16a6dcd", "release": "Rev33.1_S369"}

## Statement

The stated QED matching step divides the muon tree value by 1 + δQED, with δQED = +0.3125%, giving mµ,phys = 105.7233 MeV.

## Caution

The QED correction does not derive the loaded coefficient or account for its separate fit gap.

## Primary source

Paper 2, §3.2, Step (3): physical mass, PDF p.35: "Physical muon mass: mµ,phys = mtreeµ /(1 + δQED ) = 105.7233 MeV (+0.061% PDG; Appendix X carries the rounded +0.06%)."

## Machine

- url: /library-v2/LIB2-126/
- content_sha256: d56323618efbf640d092b6b6576adb8ad8e8c56d8a10c9c4edf0d1f97df5b8ef
- candidate_ids: C2-019

## Freshness

- BUILD_STAMP S371a · 2026-09-26T22:53Z · master 01d1a5873ede42f5 · cut 9dcc6ce9a8ee3e02
- Declared volatile fields (R36): BUILD_STAMP