Isospin symmetry breaking at high spin in the mirror nuclei 35Ar and 35Cl

High-spin states in Ar-35 and Cl-35 have been populated in the Mg-24(O-16, alpha n) and Mg-24(O-16, alpha p) reactions, respectively, at a beam energy of 70 MeV. The comparison between the level schemes of these mirror nuclei shows a striking asymmetry in the population yield of high-spin analog states of positive parity, which indicates different intensities of E1 transitions connecting positive- and negative-parity structures in both nuclei. Large energy differences are observed between analog states of negative parity with configurations of dominant pure single-particle character. This results from the comparison with large-scale shell-model calculations in the s(1/2)d(3/2)f(7/2)p(3/2) valence space. It is shown that important contributions to the energy differences arise from the multipole Coulomb and the relativistic electromagnetic spin-orbit interactions.