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Measurement of two- and three-nucleon short-range correlation probabilities in nuclei
K S Egiyan1, N B Dashyan, M M Sargsian
1Yerevan Physics Institute, Yerevan 375036, Armenia.
Physical Review Letters
|April 12, 2006
Summary
Researchers measured electron scattering cross sections for light nuclei. Results reveal distinct patterns supporting models of short-range correlations (SRC) and quantify 3-nucleon SRC probabilities in nuclei.
Area of Science:
- Nuclear Physics
- Quantum Chromodynamics
Background:
- Short-range correlations (SRC) are crucial for understanding nuclear structure.
- Previous studies have primarily focused on 2-nucleon SRC.
Purpose of the Study:
- To measure inclusive electron scattering cross sections for Helium-4, Carbon-12, and Iron-56 relative to Helium-3.
- To investigate the role of 2- and 3-nucleon SRC in nuclei.
- To provide the first measurement of 3-nucleon SRC probabilities in nuclei.
Main Methods:
- Inclusive electron scattering experiments were conducted.
- Cross section ratios were measured for 4He, 12C, and 56Fe to 3He.
- Data analysis focused on specific Bjorken-x (xB) and momentum transfer squared (Q2) ranges.
Main Results:
- At Q2 > 1.4 GeV2, cross section ratios showed two distinct plateaus at 1.5 < xB < 2 and xB > 2.25.
- This observed pattern aligns with theoretical models incorporating 2- and 3-nucleon SRC.
- Per-nucleon probabilities of 3-nucleon SRC relative to A=3 were found to be 2.3 (for A=4), 3.1 (for A=12), and 4.4 (for A=56).
Conclusions:
- The study provides compelling evidence for the presence and increasing probability of 3-nucleon SRC in heavier nuclei.
- The findings validate theoretical models that include multi-nucleon correlations.
- This work establishes a new method for quantifying 3-nucleon SRC probabilities in nuclear matter.
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