Limits on GeV-scale Exotic Isotopes and constraints on Dark Matter

Dark Matter with an attractive Yukawa coupling to nucleons, at a level allowed by Direct Detection and CMB experiments, can bind to nuclei in Earth. Sexaquark DM (SDM), is an example of this type of scenario. With an expected mass ~ 1.8-2 GeV, binding would lead to formation of exotic isotopes with masses having the very challenging mass offset of O(2 amu) from standard isotopes. Predictions for abundances vary dramatically with the Yukawa coupling, due to possible resonant (and anti-resonant) DM-nuclei interactions, moreover geochemistry of residence times is in not all cases well-known, making a theoretical interpretation challenging as well. In this talk, we report results of a recent dedicated laboratory geochemical and accelerator-mass-spectrometer search for exotic isotopes of noble gases and Oxygen, having unprecedented sensitivity in this only-now-explored mass range. The implications for the SDM scenario will be discussed.