宇宙のバリオン密度は デウテリウム燃焼の速度から
Nature
|November 12, 2020
まとめ
デウテリウム燃焼反応の正確な測定はビッグバン核合成 (BBN) モデルを改善する. この研究は 初期の宇宙を理解するために 極めて重要な バリオン密度の見積もりを提供します
科学分野:
- 核天体物理学
- 宇宙学
- 粒子物理学
背景:
- ビッグバン核合成 (BBN) で形成された軽い元素.
- デュテリウムの豊富さはバリオン密度とニュートリノ種に敏感です.
- これまでのBBN予測は,D ((p,γ) 3He反応の断面の不確実性によって制限されていた.
研究 の 目的:
- ビッグバン核合成 (BBN) の計算における不確実性を減らすために.
- 原始デウテリウム濃度の測定の精度を向上させるため
- 宇宙のバリオン密度の 信頼性の高い見積もりを提供するためです
主な方法:
- 地下核天体物理学研究所 (LUNA) で宇宙線背景を最小限に抑える実験を行った.
- 高純度デュテリウムガスの標的と LUNA 400キロボルト加速器からの強い陽子束を使用した.
- 高純度ゲルマニウム検出器を使用して,D ((p,γ) 3He反応横断を測定したガンマ線.
主要な成果:
- バリオン密度の1.6%を 改善した横断データで得ました
- 実験結果は,BBNの核物理の入力における不確実性を大幅に軽減します.
- バリオン密度は 宇宙マイクロ波の背景分析と 完璧に一致する
結論:
- この研究は,ビッグバン核合成 (BBN) 計算における重要な不確実性を解決します.
- 改善された横断データにより,初期宇宙の物理学を研究するために,原始的豊富さの使用の信頼性が向上します.
- この発見により 宇宙のパラメータを より正確に理解できます
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