JLab Measurements of the ^{3}He Form Factors at Large Momentum Transfers

Area of Science:

• Nuclear Physics
• Quantum Chromodynamics
• Particle Physics

Background:

• Helium-3 (³He) is a fundamental three-body nuclear system.
• Understanding ³He's structure is crucial for nuclear physics.
• Electron scattering experiments probe nuclear structure via form factors.

Purpose of the Study:

• Extract charge (F_C) and magnetic (F_M) form factors of ³He.
• Investigate the kinematic range of 25 fm⁻² ≤ Q² ≤ 61 fm⁻².
• Search for diffraction minima in ³He form factors.

Main Methods:

• Elastic electron scattering experiments at Jefferson Lab's Hall A.
• Coincident detection of scattered electrons and ³He recoil nuclei.
• Utilizing High Resolution Spectrometers for precise measurements.

Main Results:

• Evidence for a second diffraction minimum in the magnetic form factor of ³He at Q² = 49.3 fm⁻².
• Evidence for a second diffraction minimum in the charge form factor of ³He at Q² = 62.0 fm⁻².
• Observed minima align with theoretical predictions within the experimental Q² range.

Conclusions:

• The experimental findings support theoretical models of the three-body nuclear problem.
• Measurements provide valuable data for refining nuclear interactions and computational methods.
• The study enhances our understanding of subatomic particle interactions and nuclear structure.