diff --git a/research/hypotheses/hyp-001.md b/research/hypotheses/hyp-001.md
index 3387971f2..f1da832f0 100644
--- a/research/hypotheses/hyp-001.md
+++ b/research/hypotheses/hyp-001.md
@@ -4,6 +4,12 @@ title: "Transformer attention heads as structural correspondences (Q/K/V ↔ cel
 stage: candidate
 created: 2026-05-23
 last_verified: 2026-05-23
+blocked_by:
+  - id: DLW-55-56-yanase-verification
+    description: "柳瀬訳 DLW 55/56 の直接照合が未完了"
+    blocks: promotion_to_verified
+    condition: "verified:true かつ confirmed_reference に昇格するまで"
+    note: "Web経由の原文取得全滅（403）。書架での実物確認のみ有効。"
 promotion_history:
   - date: 2026-05-23
     from: exploration
diff --git a/research_os/tasks/mechanism_mapping.py b/research_os/tasks/mechanism_mapping.py
index 63ac0b754..78fc69c70 100644
--- a/research_os/tasks/mechanism_mapping.py
+++ b/research_os/tasks/mechanism_mapping.py
@@ -356,6 +356,25 @@ def run(hypothesis: dict, dry_run: bool = True) -> MechanismMappingResult:
                     hypothesis,
                   )
 
+    # blocked_by フィールドが promotion_to_verified をブロックしている場合、
+    # candidate への到達はできても verified への昇格は抑止する。
+    # blocked_by: のみ（値なし）で None になる場合と非リスト型を防御する。
+    blocked_by = hypothesis.get("blocked_by") or []
+    if not isinstance(blocked_by, list):
+        blocked_by = []
+    promotion_blockers = [
+        b for b in blocked_by
+        if isinstance(b, dict) and b.get("blocks") == "promotion_to_verified"
+    ]
+    if promotion_blockers and promotion.get("to") not in (
+        PromotionTarget.STAY_EXPLORATION.value,
+        PromotionTarget.REJECT.value,
+    ):
+        promotion["blocked_by"] = [b.get("id") for b in promotion_blockers if b.get("id")]
+        promotion["block_note"] = "; ".join(
+            b.get("description") or b.get("id") or "unknown" for b in promotion_blockers
+        )
+
     return MechanismMappingResult(
         status=status,
         dry_run=dry_run,