  The discovery of the Higgs boson marks a key ingredient to establish the
electroweak structure of the Standard Model. Its non-abelian gauge structure
gives rise to, yet unobserved, non-perturbative baryon and lepton number
violating processes. We propose to use cosmic ray air showers, as measured at
the Pierre Auger Observatory, to set a limit on the hadronic production cross
section of sphalerons. We identify several observables to discriminate between
sphaleron and QCD induced air showers.
