Minimal Left-Right Symmetric Dark Matter

Abstract

We show that left-right symmetric models can easily accommodate stable TeV-scale dark matter particles without the need for an ad-hoc stabilizing symmetry. The stability of a newly introduced multiplet arises either accidentally as in the Minimal Dark Matter framework or comes courtesy of the remaining unbroken ${\mathbb{Z}}_2$ subgroup of $B-L$. Only one new parameter is introduced: the mass of the new multiplet. As minimal examples we study left-right fermion triplets and quintuplets and show that they can form viable two-component dark matter. This approach is in particular valid for $SU(2)\times SU(2)\times U(1)$ models that explain the recent diboson excess at ATLAS in terms of a new charged gauge boson of mass 2 TeV.

Comments: 6 pages, 4 figures; minor improvements; to appear in PRL