Monophoton signals in electron-positron colliders in a simplified E6SSM

TL;DR

This paper investigates the mono-photon signature from inert higgsino dark matter in the E6SSM at future electron-positron colliders, highlighting its detectability and potential for dual dark matter evidence.

Contribution

It identifies the inert chargino pair production with a photon as the best probe for inert higgsino dark matter in the E6SSM at 500 GeV colliders, a novel focus.

Findings

Inert chargino pair production with a photon is the most promising detection channel.

The mono-photon signal is unlikely to be observed at the LHC.

Dual detection in collider and direct detection experiments could confirm a two-component dark matter scenario.

Abstract

The mono-photon signature emerging in an E6 Supersymmetric Standard Model (E6SSM) from inert higgsino Dark Matter (DM) is analyzed at future $e^+e^-$ colliders. As the inert neutral and charged higgsinos are nearly degenerate, the inert chargino is a rather long lived particle and the charged particle associated with its decay to the inert higgsino is quite soft. We show that the pair production of inert charginos at a 500 GeV electron-positron collider with an initial or final state photon is the most promising channel for probing the inert higgsino as one DM candidate within the E6SSM. We also emphasize that this signal has no chance of being observed at the Large Hadron Collider with higher energy and/or luminosity. Finally, we remark that, combined with a DM signal produced in Direct Detection experiments involving an active higgsino state as the second DM candidate, this dual evidence could point to a two-component DM version of the E6SSM.