Flavor and collider signatures of asymmetric dark matter

Abstract

We consider flavor constraints on, and collider signatures of, asymmetric dark matter (ADM) via higher dimension operators. In the supersymmetric models we consider, $R$-parity-violating (RPV) operators carrying $B\ensuremath{-}L$ interact with $n$ dark matter particles $X$ through an interaction of the form $W={X}^{n}{\mathcal{O}}_{B\ensuremath{-}L}$, where ${\mathcal{O}}_{B\ensuremath{-}L}=q\ensuremath{\ell}{d}^{c}$, ${u}^{c}{d}^{c}{d}^{c}$, $\ensuremath{\ell}\ensuremath{\ell}{e}^{c}$. This interaction ensures that the lightest ordinary supersymmetric particle is unstable to decay into the $X$ sector, leading to a higher multiplicity of final state particles and reduced missing energy at a collider. Flavor-violating processes place constraints on the scale of the higher dimension operator, impacting whether the LOSP decays promptly. While the strongest limitations on RPV from $n\ensuremath{-}\overline{n}$ oscillations and proton decay do not apply to ADM, we analyze the constraints from meson mixing, $\ensuremath{\mu}\ensuremath{-}e$ conversion, $\ensuremath{\mu}\ensuremath{\rightarrow}3e$ and $b\ensuremath{\rightarrow}s{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$. We show that these flavor constraints, even in the absence of flavor symmetries, allow parameter space for prompt decay to the $X$ sector, with additional jets and leptons in exotic flavor combinations. We study the constraints from existing 8 TeV LHC Supersymmetry (SUSY) searches with (i) 2--6 jets plus missing energy and (ii) 1--2 leptons, 3--6 jets plus missing energy, comparing the constraints on ADM-extended supersymmetry with the usual supersymmetric simplified models.