Fundamental study towards understanding of nucleus structure from Quantum Chromodynamics

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H06002
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: University of Tsukuba
• Principal Investigator: Yamazaki Takeshi 筑波大学, 数理物質系, 准教授 (00511437)
• Research Collaborator: NAMEKAWA Yusuke ; KURAMASHI Yoshinobu ; SASAKI Shoichi ; ISHIKAWA Ken-ichi ; SHINTANI Eigo ; KAKAZU Junpei ; TSUKAMOTO Natsuki
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 格子QCD

Outline of Final Research Achievements

The final goal of this project is to quantitatively understand the properties of nuclei, such as their mass and structure, from the first principle calculation of Quantum Chromodynamics (QCD), i.e., lattice QCD, which can directly calculate the characteristic structure of QCD, such as quark and gluon→nucleon→nucleus. We calculated the binding energy of the deuteron, which has the smallest mass number, because the nucleus study from lattice QCD is at an initial stage. The result is in good agreement with the expected value from the experiment, although the error is still large. It is an encouraging result to lay the foundation of the nucleus study from lattice QCD. Furthermore, we carried out calculations for the pion and nucleon form factors, which can be regarded as a pilot study for nucleus structure calculation. The results from those calculations agree with the experiments. Moreover, we proposed a new method to calculate scattering amplitudes using lattice QCD.

Free Research Field

素粒子理論

Academic Significance and Societal Importance of the Research Achievements

原子核は核子間の強い力により核子多体系束縛状態として存在している。このことは実験的に良く知られているが、強い力の第一原理であるQCDを用いて理解する事は非常に難しい。そのため、クォークが素粒子の地位を確立した現在でも、原子核の理論研究には核子を有効自由度とした模型計算が多く用いられている。本研究成果は、この状況を打破し、有効模型計算を用いずに、強い力の第一原理計算から原子核の性質を理解するための基礎を構築する上で非常に重要なものである。