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Extracting Neutron-Neutron Interaction Strength and Spatiotemporal Dynamics of Neutron Emission from the Two-Particle
Dawei Si1, Sheng Xiao1, Zhi Qin1
1Tsinghua University, Department of Physics, Beijing 100084, China.
Physical Review Letters
|June 23, 2025
Summary
Researchers measured neutron-neutron (nn) correlations in heavy-ion collisions. This study provides new insights into nn interactions and the size of the neutron emission source.
Area of Science:
- Nuclear Physics
- Heavy-Ion Collisions
- Quantum Correlations
Background:
- Understanding neutron-neutron (nn) interactions is crucial for nuclear structure and forces.
- Previous methods for measuring nn interactions have limitations.
- Heavy-ion collisions offer a unique environment to study nuclear forces.
Purpose of the Study:
- To measure the neutron-neutron (nn) correlation function in heavy-ion reactions.
- To extract the nn scattering parameters and the space-time size of the neutron emission source.
- To investigate the potential of heavy-ion collisions for studying nn interactions and charge symmetry breaking.
Main Methods:
- Measurement of the nn correlation function in 25 MeV/u 124Sn+124Sn reactions.
- Application of the Lednický-Lyuboshitz approach for simultaneous extraction of parameters.
- Analysis of momentum-gated correlation functions.
Main Results:
- The nn scattering length and effective range were determined.
- The reduced space-time size of the neutron emission source was extracted as 4.12±0.12 fm.
- A momentum dependence of the space-time size was observed, with values of 2.8±0.1 fm for high momentum and 4.9±0.2 fm for low momentum neutrons.
Conclusions:
- Heavy-ion collisions are an effective method for measuring nn interactions.
- The results are consistent with low-energy scattering data, supporting charge symmetry breaking studies.
- The extracted space-time size of the neutron emission source depends on the pair momentum.
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