Elko Field Theory and the Nature of Elko Darkness

TL;DR

This paper demonstrates that Elko dark matter candidates are gauge-invariant, can interact with Standard Model particles via electroweak currents, and discusses their non-locality which complicates direct detection but opens avenues for indirect experiments.

Contribution

It introduces a gauge-invariant formulation of Elko fields, establishes their potential interactions with Standard Model particles, and discusses their non-local properties affecting detection strategies.

Findings

Elko fields are gauge-invariant under local transformations.

Elko symmetry currents can couple with electroweak currents.

Elko fields exhibit non-locality, impacting detection methods.

Abstract

We show that the Elko Lagrangian dark matter candidate is gauge-invariant under local gauge transformations and that non-abelian gauge invariance can be set up quite naturally. This leads naturally to Elko symmetry currents. These Elko symmetry currents can then be coupled with the symmetry currents of the Electroweak theory to form interaction Hamiltonian densities, thus providing a natural mechanism for Elko particles to interact directly with Standard Model matter in addition to the Higgs particle. This could have profound implications for the detection of Elko at the LHC. We also show that in a certain sense Elko fields are non-local even along the axis of locality. This may make direct detection of Elko difficult. We propose that Elko would therefore still seem dark to us, as far as direct detection efforts are concerned. We propose however, that the allowed gauge interactions between Elko and the electroweak sector of the Standard Model may result in the possibility of new experiments to be devised to look for Elko indirectly via studying the Standard Model particles that are involved in an Elko interaction. Such new experiments could complement existing ideas of developing experiments to detect the Elko particles based on their interaction with the Higgs particle.