Effects of temperature and density on the two-nucleon momentum correlation function from excited single nuclei

摘要: Two-nucleon momentum correlation functions are investigated for different single thermal sources
at given initial temperature (T ) and density (ρ). To this end, the evolutions of various single
excited nuclei at T = 1 − 20 MeV and ρ = 0.2 - 1.2 ρ0 are simulated using the thermal isospindependent quantum molecular dynamics (T hIQMD) model. Momentum correlation functions of
identical proton-pairs (Cpp(q)) or neutron-pairs (Cnn(q)) at small relative momenta are calculated
by Lednick ´ y and Lyuboshitz analytical method. The results illustrate that Cpp(q) and Cnn(q) keep
sensitivities to the source size (A) at lower T or higher ρ, but almost not at higher T or lower ρ. And
the sensitivities become stronger for smaller source. Moreover, the T , ρ and A dependencies of the
Gaussian source radii are also extracted by fitting the two-proton momentum correlation functions,
and the results are consistent with the above conclusions.