2023 Fiscal Year Final Research Report
Construction of relativistic hydrodynamics involving spin and axial charge and its application to QCD plasmas
Project/Area Number |
22K20369
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Research Category |
Grant-in-Aid for Research Activity Start-up
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Allocation Type | Multi-year Fund |
Review Section |
0203:Particle-, nuclear-, astro-physics, and related fields
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Research Institution | Niigata University |
Principal Investigator |
Hongo Masaru 新潟大学, 自然科学系, 助教 (10779656)
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Project Period (FY) |
2022-08-31 – 2024-03-31
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Keywords | スピン緩和 / 近似的対称性 |
Outline of Final Research Achievements |
When continuous symmetry of a physical system is explicitly broken, the corresponding charge is no longer conserved. Considering such a situation in hadron physics, we have studied theoretical formulation and evaluation of the relaxation dynamics associated with many-body hadronic systems. In particular, we focused on the spin relaxation of baryons (nucleons and Lambda baryon), inspired by the observation of spin polarization of the Lambda baryon in relativistic heavy-ion collision experiments. As a result, we derived the effective kinetic equation describing the spin dynamics of baryons in a thermal pion gas and specifically evaluated the spin relaxation rates of nucleons and lambda baryons relying on information of their scattering processes with pions.
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Free Research Field |
ハドロン物理学
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Academic Significance and Societal Importance of the Research Achievements |
相対論的重イオン衝突実験はほぼ光速まで加速された原子核を衝突させることで1超度を越える極限状況の物質を生成し,その性質を調べることを目的としている.近年,生成されたラムダ粒子のスピン偏極が測定されたことで,実験で生成された超高温の物質が非常に大きな角速度を持っていることが示唆されている.しかしながら,生成された物質中におけるスピンのダイナミクスを記述する理論的方法はこれまで明らかになっていなかった.本研究ではこの点を解決し,生成された物質中におけるバリオン(核子・ラムダ粒子)のスピンが緩和ダイナミクスを示すことを理論的に明らかにした.
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