# LIB2-146 — The closed alpha-cell typing gives the A = 5 gap

- 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.128)
- basis: {"pdf_sha256_prefix": "b64ddcd9e16a6dcd", "release": "Rev33.1_S369"}

## Statement

With f4 = 0 closing the alpha cell, a fifth nucleon is an external τ-line with no scalar channel, so the registered single-nucleon attachment to alpha is unbound.

## Caution

The gap depends on the registered cell typing and does not determine the full charge-magnitude sector.

## Primary source

Paper 9, §4, Theorem 4.1: A = 5 gap, PDF p.132: "f4 = 0 closes the α cell, so a fifth nucleon is an external τ -line with no scalar channel: no single nucleon binds to α."

## Machine

- url: /library-v2/LIB2-146/
- content_sha256: ccf2d835373747b9f478939825d09a1804bb0ae56c205aca841062a029148ea9
- candidate_ids: C2-074

## Freshness

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