The Search for Electroweakinos

Abstract

In this review, we consider a general theoretical framework for fermionic color-singlet states—including a singlet, a doublet, and a triplet under the Standard Model SU(2)L gauge symmetry, corresponding to the bino, higgsino, and wino in supersymmetric theories—generically dubbed electroweakinos for their mass eigenstates. Depending on the relations among these states’ three mass parameters and their mixing after the electroweak symmetry breaking, this sector leads to a rich phenomenology that may be accessible in current and near-future experiments. We discuss the decay patterns of electroweakinos and their observable signatures at colliders, review the existing bounds on the model parameters, and summarize the current statuses of the comprehensive searches by the ATLAS and CMS Collaborations at the Large Hadron Collider. We also comment on the prospects for future colliders. An important feature of the theory is that the lightest neutral electroweakino can be identified as a weakly interacting massive particle cold dark matter candidate. We take into account the existing bounds on the parameters from the dark matter direct detection experiments and discuss the complementarity of the electroweakino searches at colliders.