MCTP HET BROWN BAG SEMINAR | BBN and the Unnatural Weak Scale

The discovery of a perturbatively-coupled, 125 GeV Higgs, together with the absence of LHC signals for supersymmetry, places the principle of naturalness under tension. In this talk I will discuss the possibility that the weak scale is unnatural, with its value determined environmentally in the landscape. In particular, this environmental selection may be driven by BBN: as the weak scale is increased, the abundance of Hydrogen in the early universe is rapidly depleted. That our own universe contains an O(1) fraction of primordial Helium arises as a conspiracy among the weak scale, the neutron-proton mass difference, and the planck scale.