Nucleon spin structure
Property of protons and neutrons
Summary
In particle physics, nucleon spin structure describes the partonic structure of nucleon intrinsic angular momentum (spin). The key question is how the nucleon's spin, whose magnitude is 1/2ħ, is carried by its constituent partons. It was originally expected before the 1980s that quarks carry all of the nucleon spin, but later experiments contradict this expectation. In the late 1980s, the European Muon Collaboration (EMC) conducted experiments that suggested the spin carried by quarks is not sufficient to account for the total spin of the nucleons. This finding astonished particle physicists at that time, and the problem of where the missing spin lies is sometimes referred to as the proton spin crisis.
Originally created by Sergio.ballestrero
7/30/2006, 6:35:42 PM
Modified
2/22/2025, 12:33:49 AM
Recent revisions
short description, link
/* top */Reverting Spin edits as per [[Talk:Spin (particle physics)]] and [[Wikipedia talk:WikiProject Physics]], replaced: Spin (particle physics) → Spin (physics)
/* top */[[WP:BOTREQ]]: minor clean up, replaced: Spin (physics) → Spin (particle physics)
More precise category.
Not really part of the subatomic particles category any more than any other particle physics topic.
Rescuing 1 sources and tagging 0 as dead.) #IABot (v2.0
Bot: [[User:KolbertBot|HTTP→HTTPS]] (v481)
Link to DAB page repaired
/* External links */Rem stub tag(s) (class = non-stub & non-list) using [[Project:AWB|AWB]]
The history was missing the first experiments that address the "spin crisis" at SLAC in the 1990s: E142 (structure of the neutron), E143 (structure of the proton and deuteron). I added them. They preceded E154, E155.
Add SLAC experiments; editorial cleanup
two missing spaces
