LHC Signals for a SuperUnified Theory of Dark Matter

TL;DR

The paper links astrophysical hints of dark matter to a SUSY-embedded framework with a GeV-scale dark sector that communicates with the Standard Model through kinetic mixing. It argues that radiatively generated GeV-scale breaking in G_Dark naturally yields light gauge bosons and MeV-scale DM splittings, compatible with DAMA/iDM/XDM scenarios and PAMELA/ATIC signals. Collider phenomenology features SUSY cascades that end in the dark sector, producing leptonic final states organized into lepton jets, and potentially long-lived colored states if DM carries SM charges. By integrating TODM ideas with low-energy SUSY, the work proposes distinctive, testable LHC signatures and flavor-factory probes that can decisively test this Dark Matter framework.

Abstract

A new theory of WIMP Dark Matter has been proposed, motivated directly by striking Data from the PAMELA and ATIC collaborations. The WIMP is taken to be charged under a hidden gauge symmetry G_Dark, broken near the GeV scale; this also provides the necessary ingredients for the "exciting" and "inelastic" Dark Matter interpretations of the INTEGRAL and DAMA signals. In this short note we point out the consequences of the most straightforward embedding of this simple picture within low-energy SUSY, in which G_Dark breaking at the GeV scale arises naturally through radiative corrections, or Planck-suppressed operators. The theory predicts major additions to SUSY signals at the LHC. A completely generic prediction is that G_Dark particles can be produced in cascade decays of MSSM superpartners, since these end with pairs of MSSM LSP's that in turn decay into the true LSP and other particles in the dark sector. In turn, the lightest GeV-scale dark Higgses and gauge bosons eventually decay back into light SM states, and dominantly into leptons. Therefore, a large fraction of all SUSY events will contain at least two ``lepton jets'': collections of n>= 2 leptons, with small angular separations and GeV scale invariant masses. Furthermore, if the Dark Matter sector is directly charged under the Standard Model, the success of gauge coupling unification implies the presence of new long-lived colored particles that can be copiously produced at the LHC.

Figures (4)

• Figure 1: The minimal supersymmetric model (a) and the minimal SuperDark Moose (b).
• Figure 2: Process contributing to thermal equilibrium of the $G_{Dark}$ sector.
• Figure 3: Cascade decays into the $G_{Dark}$ sector and lepton jets. The final decay to leptons can arise at the end of a variety of chains in the $G_{Dark}$ charged sector.
• Figure 4: The simplest diagram of direct production of $G_{Dark}$ sector. Similar diagrams exist for production of $\tilde{D}$ and for cases where the direct production is of a link field. Such cascades generally produce additional "lepton jets", with and without missing energy.