Pairing gap as a new observable for critical points in the region of A≈100

This study used the pairing gap to identify nuclei as candidates for critical point symmetry around [Formula: see text] and [Formula: see text]. Nuclei around [Formula: see text] display complex shape evolution and configuration crossing patterns. We utilized the experimental and algebraic frameworks of the interacting boson model (IBM) and the newly developed interacting boson-fermion model to study the isotopes of Mo and Ru. The results show significant variations in these quantities across nuclei located at the E(5) and X(5) critical points, analyzed through different observables.