陽子のグルオン重力形因子を決定する

B Duran^1,2, Z-E Meziani^3,4, S Joosten¹

¹Physics Division, Argonne National Laboratory, Lemont, IL, USA.

Nature

|March 29, 2023

まとめ

研究者は,J/ψ粒子の光生成を用いて,グルオンが支配する陽子の内部質量密度を探査した. 陽子の質量半径が電荷半径より小さいことが分かり物質の重力質量についての洞察を得ました

科学分野:

* 粒子物理学と量子クロモダイナミクス
* 核物理学と陽子の構造

背景:

* 物質の基本的な構成要素である陽子は電気的電荷,質量,スピンなどの固有の性質を持っています
* これらの性質は,量子クロモダイナミクスで説明されているように,クォークとグルオンの複雑な相互作用から生じる.
* 陽子の電荷とスピンは広く研究されていますが,その内部質量密度は,主にグルオンによるものです.

研究の目的:

* 陽子内のグルオンの重力質量密度を調査する.
* 陽子のグルオン重力形因子を決定する.
* 陽子の質量半径と電荷半径を比較する

主な方法:

J/ψ粒子の値光生成を利用した.
* グルーオンの寄与にアクセスするために小さな色二極探査機を使用した.
* グルーオン重力形因子を抽出するために実験データを分析した.

主要な成果:

* 陽子のグルオン重力形因子を決定した.
* 陽子の質量半径が電荷半径より小さいことを一貫して様々なモデルで発見した.
* 特定の半径と格子量子クロモダイナミクスの予測がいくつかのモデルで一致している.

結論:

* この研究は,陽子内のグルオン質量の分布に関する重要な洞察を提供します.
* 結果は,電荷半径と比較して,より小さな質量半径を示唆しています.
* この研究は,可視物質の重力質量におけるグルオンの役割の理解を進める.

さらに関連する動画

08:48

High-Resolution Neutron Spectroscopy to Study Picosecond-Nanosecond Dynamics of Proteins and Hydration Water

Published on: April 28, 2022

1.8K

10:27

Contrast-Matching Detergent in Small-Angle Neutron Scattering Experiments for Membrane Protein Structural Analysis and Ab Initio Modeling

Published on: October 21, 2018

12.4K

関連する概念動画

01:15

Newton's Law of Gravitation

12.9K

Our everyday observation tells us that all objects close to the Earth naturally tend to fall to the ground. Early philosophers assumed that this downward force was unique to Earth. By the 16th century, Nicolaus Copernicus (1473-1543) put forward the heliocentric theory, which suggested that Earth and other planets orbited the sun, while the Moon orbited the Earth. However, it was Isaac Newton (1642-1727) who linked these two motions together in the 17th century. He reasoned that the force of...

12.9K

01:17

The Principle of Superposition and the Gravitational Field

1.4K

The principle of superposition applies to gravitational forces of objects that are sufficiently far apart. It states that the net gravitational force on a point object is the vector sum of the gravitational forces on it due to various objects. The principle helps calculate the force by listing the individual forces and then vectorially summing them up. However, it should be noted that the principle of superposition is not always apparent. In the presence of a second force, the first force could...

1.4K

01:11

Atomic Nuclei: Larmor Precession Frequency

1.5K

The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) that causes the mass to 'wobble' around the gravitational field axis in a phenomenon called precession. Similarly, the magnetic moment (μ) of a spinning nucleus precesses due to an external magnetic field directed along the z-axis. The precession of the magnetic moment vector about the magnetic field is called Larmor precession,...

1.5K

03:37

Subatomic Particles

93.0K

Dalton was only partially correct about the particles that make up matter. All matter is composed of atoms, and atoms are composed of three smaller subatomic particles: protons, neutrons, and electrons. These three particles account for the mass and the charge of an atom.

93.0K

01:24

Comparison Between Electrical And Gravitational Forces

2.8K

There are four fundamental forces in nature: the gravitational force, the electromagnetic force, the strong nuclear force, and the weak nuclear force. To compare the numerical strengths of the first two, take two particles of the same kind. Since electrons are fundamental particles, they are a good example.
Since both are inverse square law forces, the distance gets canceled when the ratio of the two forces is considered. Instead, the ratio of the electrical and gravitational forces depends on...

2.8K

01:25

Atomic Weight

9.1K

Protons and neutrons have approximately the same mass, about 1.67 × 10-24 grams. Scientists arbitrarily define this amount of mass as one atomic mass unit (amu) or one Dalton. Electrons are much smaller in mass than protons, weighing only 9.11 × 10-28 grams, or about 1/1800 of an atomic mass unit. As a result, they do not contribute much to an element's overall atomic mass. This means that, when considering atomic mass, it is customary to ignore the mass of any electrons and...