The proton spin crisis (or proton spin puzzle) is a theoretical crisis precipitated by a 1987 experiment by the European Muon Collaboration (EMC), [1] which tried to determine the …

質子自旋危機 （英語： Proton spin crisis），有時稱作「質子自旋之謎」，是1987年的一次實驗促成的理論危機，該實驗試著測定 質子 自旋的組成結構，由 歐洲μ子共同研究 （EMC）實施 …

2020年11月23日 · There are two established approaches to look at the composition of the proton spin: the frame-independent spin structure (or the Ji sum rule) and the infinite-momentum …

2007年3月23日 · Unlike classical tops, however, the spin of these particles is an intrinsic quantum mechanical phenomenon. This spin is responsible for many fundamental properties of matter, …

2017年3月29日 · Protons are one of the three particles that make up atoms, the building blocks of the universe. A proton's spin is one of its most basic properties. Because protons are in part …

2015年6月4日 · Spin is a quantum-mechanical property, akin to the angular momentum of a classical sphere rotating on its axis, except it comes in discrete units of integer or half-integer …

2020年9月2日 · Much theoretical and experimental progress has been made in understanding the origins of the proton spin. In this review, we will discuss what we have learned so far, what are …

2021年1月8日 · Where does the proton spin come from? The proton is a spin-1/2 particle. It would seem reasonable to assume that its spin comes from the simple arithmetic of three component …

The “proton spin crisis” was introduced in the late 1980s, when the EMC-experiment revealed that little or nothing of a proton’s spin seemed to be carried by its quarks. The main objective of this …

Spin is described mathematically as a vector for some particles such as photons, and as a spinor or bispinor for other particles such as electrons. Spinors and bispinors behave similarly to …