Study of hadron structures from a new viewpoint

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K05365
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Gunma National College of Technology
• Principal Investigator: Takahashi Toru 群馬工業高等専門学校, 一般教科(自然), 准教授 (70467405)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 格子ＱＣＤ / ＱＣＤ / ハドロン物理 / フレーバー / ヘビークォーク / エントロピー

Outline of Final Research Achievements

(1) We performed lattice QCD study of the internal structures of charmed hadrons. We evaluated the flavor structures of the Lambda baryons with various (fictitious) 　valence quark masses. As a result, we succeeded in determining the internal structure of the Lambda baryons. We also computed the electromagnetic form factors of various charmed baryons and investigated their properties. (2) We studied the thermalization process of the Yang-Mills theory based on the Husimi-Wehrl(HW) entropy, and we confirmed the entropy growth in the early stage of the thermalization process. We also found that the saturation time of the HW entropy is comparable with that of pressure isotropization. (3) We evaluated the correlations among quarks by means of the entropy defined from the density matrix in the color space, and found that the interquark correlations are reflected in thus defined entropy.

Free Research Field

ハドロン物理

Academic Significance and Societal Importance of the Research Achievements

本研究では、それまでとは異なる観点・手法を用いてハドロン・クォークの性質の研究を行った。異なる対称性に着目したΛ粒子の解析では、不定性が大きく解析が困難だったΛ粒子の内部構造を同定するなど一定の成果を得た。また、カラー自由度に着目したクォーク相関の研究においても、事前の期待通りの結果を得ている。これらの手法は応用が可能であり、今後の研究につながることが期待される。