Revealing the neutron density distribution in the nucleus is one of the crucial tasks of nuclear physics. Within the framework of the ultrarelativistic quantum molecular dynamic model followed by a correlation afterburner program, we investigate the effects of the initial neutron density distribution on the charged-pion yield ratio $\pi^{ -}/\pi^{ +}$, the two-pion momentum correlation function, and the emission source dimension. It is found that the $\pi^{ -}/\pi^{ +}$ ratio is sensitive to the initial neutron density distribution and the impact parameter, especially for collisions at large impact parameter. However, the charge splitting in the correlation functions between positively $\pi^{ +}\pi^{ +}$ and negatively $\pi^{ -}\pi^{ -}$, as well as the source radii and volumes extracted exhibit a stronger dependence on the initial neutron density distribution, but a weaker dependence on the impact parameter. The present study highlights that $\pi^{ +}\pi^{ +}$ and $\pi^{ -}\pi^{ -}$ correlation functions in heavy-ion collisions could be used to probe the initial neutron density distribution of nuclei.
Categories: nucl-th