Nucleon charge and magnetisation distributions: Flavour separation and zeroes

Area of Science:

• * Quantum Field Theory
• * Hadron Physics
• * Nuclear Physics

Background:

• * Understanding nucleon structure is crucial in quantum chromodynamics.
• * Electromagnetic form factors probe the distribution of charge and magnetism within nucleons.
• * Previous models often require parameterization, limiting predictive power.

Purpose of the Study:

• * To provide parameter-free predictions for nucleon elastic electromagnetic form factors.
• * To investigate the flavor separation of these form factors.
• * To explore nucleon properties at large momentum transfer (Q^2).

Main Methods:

• * Employing a symmetry-preserving truncation of quantum field equations.
• * Calculating all nucleon elastic electromagnetic form factors.
• * Analyzing flavor separation and behavior at high Q^2.

Main Results:

• * Parameter-free predictions for nucleon elastic electromagnetic form factors across a range of Q^2.
• * The proton electric form factor (G_E^p) exhibits a zero, while the neutron's (G_E^n) does not.
• * G_E^n > G_E^p observed over a significant high Q^2 domain due to valence d-quark behavior.

Conclusions:

• * The model successfully predicts key features of nucleon form factors without free parameters.
• * The distinct behavior of G_E^p and G_E^n highlights differences in quark contributions.
• * These parameter-free predictions offer testable benchmarks for ongoing and future experiments.