mesons in a magnetic field

磁場中での中間子

Gubler, P.*; 服部 恆一*; Lee, S. H.*; 岡 眞   ; 尾崎 翔*; 鈴木 渓*   

Gubler, P.*; Hattori, Koichi*; Lee, S. H.*; Oka, Makoto; Ozaki, Sho*; Suzuki, Kei*

高エネルギー重イオン衝突実験などで強い磁場ができた時に、その中に作られたチャームを含む中間子がどのようなスペクトルを示すかを、QCD和則の方法を用いて計算し、その成果をまとめた。擬スカラー中間子にベクトルD中間子が混合する効果および、電荷を持った中間子が磁場中でランダウ準位構造を示す効果を詳細に解析し、中間子の質量変化として現れることを示した。

We investigate the mass spectra of open heavy flavor mesons in an external constant magnetic field within QCD sum rules. Spectral ansatze on the phenomenological side are proposed in order to properly take into account mixing effects between the pseudoscalar and vector channels, and the Landau levels of charged mesons. The operator product expansion is implemented up to dimension-5 operators. As a result, we find for neutral mesons a significant positive mass shift that goes beyond simple mixing effects. In contrast, charged mesons are further subject to Landau level effects, which together with the mixing effects almost completely saturate the mass shifts obtained in our sum rule analysis.