Astrophysical probes of unification

Traditional ideas for testing unification involve searching for the decay of the proton and its branching modes. We point out that several astrophysical experiments are now reaching sensitivities that allow them to explore supersymmetric unified theories. In these theories the electroweak-mass dark matter particle can decay, just like the proton, through dimension 6 operators with lifetime $\sim {10}^{26}\mathrm{s}$. Interestingly, this time scale is now being investigated in several experiments including ATIC, PAMELA, HESS, and Fermi. Positive evidence for such decays may be opening our first direct window to physics at the supersymmetric unification scale of $M_{\mathrm{GUT}}\sim {10}^{16}\mathrm{GeV}$, as well as the TeV scale. Moreover, in the same supersymmetric unified theories, dimension 5 operators can lead a weak-scale superparticle to decay with a lifetime of $\sim 100\mathrm{s}$. Such decays are recorded by a change in the primordial light element abundances and may well explain the present discord between the measured Li abundances and standard big bang nucleosynthesis, opening another window to unification. These theories make concrete predictions for the spectrum and signatures at the LHC as well as Fermi.