Sensitivity of large cosmic ray air shower experiments for new physics searches

Searches for physics beyond the Standard Model of particle physics are performed at accelerators worldwide. Although having poorer detection capabilities and large beam uncertainties, ultra high energy cosmic ray (UHECR) experiments present a unique opportunity to look for new physics far beyond the TeV. Nearly horizontal energetic neutrinos, seeing a large atmospheric target volume and with negligible background from "ordinary" cosmic rays, are ideal to explore rare processes. The sensitivity of present and planned experiments to different new physics scenarios is estimated, including mini black-holes, excited leptons and leptoquarks.