反陽子対陽子電荷対質量比の高精度比較
S Ulmer1, C Smorra2, A Mooser1
1RIKEN, Ulmer Initiative Research Unit, Wako, Saitama 351-0198, Japan.
Nature
|August 14, 2015
まとめ
この研究では,反陽子と陽子の性質を正確に比較し,電荷,対数,時間逆転 (CPT) の対称性をアトー電子ボルトの精度で確認した. CPTの不変性を強く支持し 物理学の基本原理を検証しています
科学分野:
- 粒子物理学
- 基本的な対称性
- 反物質の研究
背景:
- チャージ・パリティ・タイム・リバースメント (CPT) の不変性は,物質と反物質の対称性を示唆する標準モデルの礎石である.
- これまでのCPT試験は間接的な方法に頼っており,物質と反物質の特性を直接,高精度で比較することはほとんどない.
- ロレンツ対称性とは,時空変換下での物理法則の不変性であり,CPTの不変性と深く結びついている.
研究 の 目的:
- 反陽子と陽子の電荷対質量比を高精度で比較する.
- 物質と反物質の基本的な性質を比較して,CPT対称性を直接テストする.
- CPTとローレンツ対称性の潜在的な違反に新しい限界を設定し,弱い同等性原理をテストする.
主な方法:
- 単一の反陽子と水素イオン (H-) のサイクロトロン周波数を制限し測定するためにペニングトラップシステムを利用した.
- 高い精度で電荷と質量の比率を比較するために1万3千以上の周波数測定を行った.
- 分析したサイクロトロン周波数は 約29.6メガヘルツ
主要な成果:
- 陽子に対する反陽子の電荷対質量比は,CPTの不変性と一致し,精度は1兆分の69でした.
- この結果は,CPT対称性がアトー電子ボルトエネルギースケールで成立することを示しています.
- 星の変動 (<720 parts per trillion) と重力異常パラメータ (gadgadα − 1gadgad < 8.7 × 10(-7) に対して厳格な限界を確立した.
結論:
- この研究は,物質と反物質を比較することによって,これまでで最も正確なCPT対称性テストを提供します.
- この発見は,CPT定理と標準モデルの妥当性を強化しています.
- この結果は,一般相対性理論に意味を持つ,バリオン反物質の弱い同等性原理の重要なテストを提供します.
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