中性子と陽子の質量差の Ab initio 計算
Sz Borsanyi1, S Durr2, Z Fodor3
1Department of Physics, University of Wuppertal, D-42119 Wuppertal, Germany.
まとめ
原子の安定性にとって極めて重要な中性子と陽子の質量差は,電磁と質量イソスピン効果の競合から生じる. 私たちの研究は,高度な計算方法を使用して,この分割を正確に定量化しています.
科学分野:
- 核物理学 核物理学とは
- 素粒子物理学 素粒子物理学について
- 量子クロモダイナミクスは,量子クロモダイナミクスの
背景:
- 原子の安定性は,中性子と陽子の質量差,小さいが重要な値に依存する.
- この質量差は,平均陽子中性子質量の約0.14%である.
- この質量差の偏差は,劇的に異なる宇宙をもたらすだろう.
研究 の 目的:
- 中性子と陽子の質量差の根本的な起源を解明する.
- 電子磁気と質量イソスピン断裂効果の相互作用を調査する.
- この質量差を格子量子染色力学を使って正確に計算する.
主な方法:
- 網羅量子クロモダイナミクス (LQCD) と網羅量子電動力学 (LQCDED) の計算を活用した.
- 計算に4つの非退化ウィルソンフェルミオン味を用いた.
- 高精度で中性子・陽子質量分裂を計算した.
主要な成果:
- 中性子-陽子質量分裂が0より大きく5標準偏差で,300 keVの精度で決定されました.
- Σ, Ξ, D, Ξcc を含む他のイソスピンマルチプレート内の計算された質量分割.
- いくつかのマルチプレート分割では,現在の実験測定を上回る精度を達成しました.
結論:
- 中性子と陽子の質量差は,電磁性および質量イソスピン破裂の間の競争の結果である.
- 格子QCDとQEDは,基本的な粒子の性質を計算するための強力なフレームワークを提供します.
- この方法論は,他の粒子の質量差を正確に決定するために拡張することができます.
さらに関連する動画
10:27Contrast-Matching Detergent in Small-Angle Neutron Scattering Experiments for Membrane Protein Structural Analysis and Ab Initio Modeling
Published on: October 21, 2018
13.2K
05:51Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
6.8K
関連する概念動画
Nuclear Binding Energy
15.4K
The difference between the calculated and experimentally measured masses is known as the mass defect of the atom. In the case of helium-4, the mass defect indicates a “loss” in mass of 4.0331 amu – 4.0026 amu = 0.0305 amu. The loss in mass accompanying the formation of an atom from protons, neutrons, and electrons is due to the conversion of that mass into energy that is evolved as the atom forms. The nuclear binding energy is the energy produced when the atoms’ nucleons...
15.4K
Subatomic Particles
120.1K
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.
120.1K
High-Resolution Mass Spectrometry (HRMS)
2.9K
The resolution of a mass spectrometer depends on the efficiency of separating ions with different ion masses. The mass of an atom is approximated to the sum of the masses of protons and neutrons inside, considering the masses of protons and neutrons as equal. However, the masses of the proton (1.6726 × 10−24 g) and neutron (1.6749 × 10−24 g) are not truly equal. There is a minor error in the expression of atomic masses relative to the simplest atom of hydrogen. For...
2.9K
Atomic Weight
15.2K
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...
15.2K
Nuclear Stability
24.5K
Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10−15 meters, a nucleus is quite small compared to the radius of the entire atom, which is about 10−10 meters. Nuclei are extremely dense compared to bulk matter, averaging 1.8 × 1014 grams per cubic centimeter. If the earth’s density were equal to the average nuclear density, the earth’s radius would be only about 200 meters.
To hold positively...
To hold positively...
24.5K
Atomic Mass
72.7K
Atoms — and the protons, neutrons, and electrons that compose them — are extremely small. For example, a carbon atom weighs less than 2 × 10−23 g. When describing the properties of tiny objects such as atoms, we use appropriately small units of measure, such as the atomic mass unit (amu). The amu was originally defined based on hydrogen, the lightest element, then later in terms of oxygen. Since 1961, it has been defined with regard to the most abundant isotope of carbon,...
72.7K
