2025/01/16 by Si, Dawei, Xiao, Sheng, Qin, Zhi +25 · 5 citations
#FOS: Physical sciences #Nuclear Experiment (nucl-ex)
paper · doi:10.48550/arxiv.2501.09576
The neutron-neutron (nn) correlation function has been measured in 25 MeV/u 124Sn+124Sn reactions. Using the Lednický-Lyuboshitz approach, the nn scattering length and effective range (f0nn, d0nn), as well as the reduced space-time size R(0) of the neutron emission source are simultaneously extracted as (18.9+1.3-1.2 fm, 1.9+1.3-1.0 fm) and 4.12 ± 0.12 fm, respectively. The measured nn scattering length is consistent with the results obtained in the low-energy scattering 2\rm H(π-,γ)2n, indicating heavy-ion collisions can serve as an effective approach for measuring nn interactions and further investigating the charge symmetry breaking of nuclear force. The space-time size extracted from momentum-gated correlation functions exhibits clear dependence on the pair momentum, with R(0)=2.8 ± 0.1 fm and 4.9 ± 0.2 fm being determined for the high and low momentum neutrons, respectively.