Extract neutron-neutron interaction strength and spatial-temporal dynamics of neutron emission from two-particle correlation function

Abstract

The neutron-neutron ($nn$) correlation function has been measured in 25 MeV/u ${}^{124}$Sn+${}^{124}$Sn reactions. Using the Lednický-Lyuboshitz approach, the $nn$ scattering length and effective range ($f_0^{nn}$, $d_0^{nn}$), as well as the reduced space-time size $R^{(0)}$ of the neutron emission source are simultaneously extracted as ($18.9_{-1.2}^{+1.3}$ fm, $1.9_{-1.0}^{+1.3}$ fm) and $4.12\pm 0.12$ fm, respectively. The measured $nn$ scattering length is consistent with the results obtained in the low-energy scattering ${}^2\mathrm{H}({\pi }^{-},\gamma )2n$, 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 $R^{(0)}=2.8\pm 0.1$ fm and $4.9\pm 0.2$ fm being determined for the high and low momentum neutrons, respectively.

References in corpus (8)

• Systematics of central heavy ion collisions in the 1A GeV regime
• Correlations and Characterization of Emitting Sources
• CSHINE for studies of HBT correlation in Heavy Ion Reactions
• The Emission Order of Hydrogen Isotopes via Correlation Functions in 30 MeV/u Ar+Au Reactions
• Nucleon-nucleon momentum correlation function as a probe of the density distribution of valence neutron in neutron-rich nucleus
• Imaging Freeze-out Sources and Extracting Strong Interaction Parameters in Relativistic Heavy-Ion Collisions
• A CsI hodoscope on CSHINE for Bremsstrahlung γ-rays in Heavy Ion Reactions
• The neutron array of the compact spectrometer for heavy ion experiments in Fermi energy region

Cited by in corpus (4)

• Linear Response of CsI(Tl) Crystal to Energetic Photons below 20 MeV
• Probing the Three-dimension Emission Source and Neutron Skin via $\pi$-$\pi$ Correlations in Heavy-Ion Collisions
• Experimental Study of Bremsstrahlung Gamma Ray Emission and Short-Range Correlations in ${}^{124}$Sn+${}^{124}$Sn Collisions at 25 MeV/u
• Reconstructing rare particle source by femtoscopic correlations