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Two-nucleon momentum distributions measured in 3He(e,e'pp)n
R A Niyazov1, L B Weinstein, G Adams
1Old Dominion University, Norfolk, Virginia 23529, USA.
Physical Review Letters
|March 6, 2004
Summary
We measured the helium-3 (3He) (e,e'pp)n reaction. Results show fast nucleon pairs act as spectators, revealing distorted two-nucleon momentum distributions in nuclei.
Area of Science:
- Nuclear Physics
- Quantum Chromodynamics
Background:
- Understanding nucleon interactions within nuclei is crucial for nuclear physics.
- The helium-3 nucleus (3He) provides a fundamental three-body system for studying these interactions.
Purpose of the Study:
- To investigate the (e,e'pp) reaction mechanism in 3He at high momentum transfer.
- To probe the short-range structure and correlated nucleon pairs within the 3He nucleus.
Main Methods:
- Experiments were conducted using a 2.2 GeV electron beam.
- The (e,e'pp) reaction channel was measured across a broad kinematic range.
- Kinetic energy and momentum distributions of emitted nucleons were analyzed.
Main Results:
- A distinct peak in the kinetic energy distribution for "fast" nucleons (p>250 MeV/c) was observed.
- These fast proton-proton (pp) and proton-neutron (pn) pairs exhibited back-to-back correlations, acting as spectators.
- The momentum distributions indicated distortions due to nucleon-nucleon correlations.
Conclusions:
- The experiment successfully measured distorted two-nucleon momentum distributions in 3He.
- The findings support theoretical models describing nucleon behavior in few-body nuclear systems.
- This study provides insights into the role of short-range nucleon correlations.
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