The Os$^{16+}$ and Ir$^{17+}$ ions as candidates for accurate optical clock sensitive to physics beyond standard model

Abstract: We perform detailed calculations of the electronic structure of the Os$^{16+}$ ion and demonstrate that it has several metastable states which can be used for very accurate optical clocks. The clocks are highly sensitive to manifestations of the physics beyond standard model, such as time variation of the fine structure constant $\alpha$, interaction with scalar and pseudoscalar (axion) dark matter fields, local Lorentz invariance and local position invariance violations, and interaction of atomic electrons with nucleus mediated by new boson. The latter can be studied by analysing King plot for isotope shifts and its possible non-linearities since Os has 5 stable isotopes with zero nuclear spin. Similar calculations for the Ir$^{17+}$ ion spectra demonstrate very good agreement between theory and experiment. This helps to validate the method of the calculations and demonstrate that both ions are excellent candidates for the search of new physics.