Astrophysical Probes of Unification

TL;DR

<3-5 sentence high-level summary>

Abstract

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 DM particle can decay, just like the proton, through dimension six operators with lifetime ~ 10^26 sec. Interestingly, this timescale 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_GUT ~ 10^16 GeV, as well as the TeV scale. Moreover, in the same supersymmetric unified theories, dimension five operators can lead a weak-scale superparticle to decay with a lifetime of ~ 100 sec. 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.

Figures (9)

• Figure 1: A singlet fermion decaying to a lepton, slepton pair with a singlet scalar vev $\langle \tilde{s} \rangle$ insertion.
• Figure 2: MSSM neutralino decaying to a singlet LSP and an $e^+e^-$ pair. The decay is dominantly into leptons because sleptons are typically lighter than squarks.
• Figure 3: A singlet scalar $\tilde{s}$ decaying to a slepton pair with a singlet scalar vev $\langle \tilde{s} \rangle$ insertion.
• Figure 4: A way to generate the operator $S^\dagger\, 10_f H_d^\dagger 10_f$.
• Figure 5: ${\cal D}_\alpha^210_fH_u^\dagger H_d$ generated by $H_u H_d \bar{5}_{f} \bar{5}_{f} 10_{f}$ and the MSSM Yukawas