Collective excited states at small amplitude in neutron elastic scattering at low-energies

We investigate the contributions of isoscalar and isovector collective excitations in the neutron elastic scattering of ${}^{16}$O, ${}^{40}$Ca, ${}^{48}$Ca, and ${}^{208}$Pb nuclei by using a microscopic optical potential (MOP) derived from nuclear structure models based on self-consistent mean-field approaches. Particular attention is given to the role of these collective modes in shaping the imaginary part of the MOP and the resulting angular distributions. Our analysis indicates that both isoscalar and isovector contributions are significant for all considered targets, especially for light and medium targets. Furthermore, the Coulomb interaction is found to play an important role in describing absorption mechanisms and reproducing the experimental angular distributions.