Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Divergence and Curl of Magnetic Field01:26

Divergence and Curl of Magnetic Field

2.7K
The magnetic field due to a volume current distribution given by the Biot–Savart Law can be expressed as follows:
2.7K
Collisions in Multiple Dimensions: Introduction01:05

Collisions in Multiple Dimensions: Introduction

4.4K
It is far more common for collisions to occur in two dimensions; that is, the initial velocity vectors are neither parallel nor antiparallel to each other. Let's see what complications arise from this. The first idea is that momentum is a vector. Like all vectors, it can be expressed as a sum of perpendicular components (usually, though not always, an x-component and a y-component, and a z-component if necessary). Thus, when the statement of conservation of momentum is written for a...
4.4K
Atomic Nuclei: Nuclear Spin State Population Distribution01:14

Atomic Nuclei: Nuclear Spin State Population Distribution

892
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
892
Conservation of Angular Momentum01:09

Conservation of Angular Momentum

10.0K
A system's total angular momentum remains constant if the net external torque acting on the system is zero. Considering a system that consists of n tiny particles, the angular momentum of any tiny particle may change, but the system's total angular momentum would remain constant. The principle of conservation of angular momentum only considers the net external torque acting on the system. While there are internal forces exerted by different particles within the system that also produce...
10.0K
Atomic Nuclei: Nuclear Magnetic Moment00:59

Atomic Nuclei: Nuclear Magnetic Moment

992
All atomic nuclei are positively charged. When they have a nonzero spin, they behave like rotating charges. As a consequence of their charge and spin, these nuclei generate a magnetic field (B). This, in turn, gives rise to a magnetic moment (μ), which is randomly oriented in the absence of an external magnetic field. When an external magnetic field (B0) is applied, the magnetic moment vectors can align with the field or against it in 2 + 1 orientations. A hydrogen nucleus, which is just a...
992
Conservation of Angular Momentum: Application01:18

Conservation of Angular Momentum: Application

10.7K
A system's total angular momentum remains constant if the net external torque acting on the system is zero. Examples of such systems include a freely spinning bicycle tire that slows over time due to torque arising from friction, or the slowing of Earth's rotation over millions of years due to frictional forces exerted on tidal deformations. However in the absence of a net external torque, the angular momentum remains conserved. The conservation of angular momentum principle requires a...
10.7K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Ultrahigh-energy gamma-ray emission associated with black hole-jet systems.

National science review·2025
Same author

Ultra-high energy cosmic neutrinos from gamma-ray bursts.

Fundamental research·2024
Same author

A concise proof of Benford's law.

Fundamental research·2024
Same author

Light speed variation from active galactic nuclei.

Science bulletin·2023
Same author

LHAASO discovery of highest-energy photons towards new physics.

Science bulletin·2023
Same author

Analyzing Transverse Momentum Spectra of Pions, Kaons and Protons in <i>p</i>-<i>p</i>, <i>p</i>-A and A-A Collisions via the Blast-Wave Model with Fluctuations.

Entropy (Basel, Switzerland)·2021
Same journal

Erratum: Bacterial Turbulence at Compressible Fluid Interfaces [Phys. Rev. Lett. 136, 138301 (2026)].

Physical review letters·2026
Same journal

Unveiling Light-Quark Yukawa Flavor Structure via Dihadron Fragmentation at Lepton Colliders.

Physical review letters·2026
Same journal

Adaptable Route to Fast Coherent State Transport via Bang-Bang-Bang Protocols.

Physical review letters·2026
Same journal

Topological Transition and Emergence of Elasticity of Dislocation in Skyrmion Lattice: Beyond Kittel's Magnetic-Polar Analogy.

Physical review letters·2026
Same journal

Pound-Drever-Hall Method for Superconducting-Qubit Readout.

Physical review letters·2026
Same journal

Coupling a ^{73}Ge Nuclear Spin to an Electrostatically Defined Quantum Dot in Silicon.

Physical review letters·2026
See all related articles

Related Experiment Video

Updated: May 14, 2025

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
08:51

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

Published on: August 18, 2017

9.0K

First Extraction of Transverse-Momentum Dependent Helicity Distributions.

Ke Yang1, Tianbo Liu2,3, Peng Sun4,5

  • 1Peking University, School of Physics, Beijing 100871, China.

Physical Review Letters
|April 11, 2025
PubMed
Summary
This summary is machine-generated.

This study presents the first global analysis of proton helicity distributions. Results show nonzero signals for up and down quarks, with polarization varying by quark flavor and momentum.

More Related Videos

Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow
13:02

Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow

Published on: February 27, 2016

12.1K
A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
00:07

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference

Published on: September 5, 2019

8.3K

Related Experiment Videos

Last Updated: May 14, 2025

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
08:51

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

Published on: August 18, 2017

9.0K
Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow
13:02

Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow

Published on: February 27, 2016

12.1K
A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
00:07

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference

Published on: September 5, 2019

8.3K

Area of Science:

  • Particle Physics
  • Quantum Chromodynamics
  • Hadron Structure

Background:

  • Understanding the proton's internal structure is crucial in particle physics.
  • Helicity distributions provide insights into quark and gluon spin contributions.
  • Previous analyses often relied on collinear factorization.

Purpose of the Study:

  • To conduct the first global analysis of transverse-momentum dependent helicity distributions of the proton.
  • To investigate the role of quark flavors and transverse momentum in proton polarization.
  • To compare results with collinear factorization analyses.

Main Methods:

  • Performed a next-to-leading order (NLO) analysis.
  • Utilized next-to-next-to-leading-logarithmic (N3LL) accuracy for the evolution factor.
  • Incorporated existing experimental data for global fitting.

Main Results:

  • Determined nonzero helicity distributions for up and down quarks.
  • Found k_{T}-integrated polarization consistent with collinear factorization results.
  • Observed that large-x quarks become less polarized, while small-x quarks become more polarized with increasing transverse momentum.
  • Loosely constrained distributions for other quark flavors.

Conclusions:

  • The analysis provides a comprehensive understanding of proton spin structure.
  • Transverse momentum plays a significant role in modulating quark polarization within the proton.
  • Results highlight the importance of TMDs for a complete picture of hadron structure.