Identifying the nature of dark matter at $e^{-}e^{+}$ Colliders

TL;DR

This paper explores how future electron-positron colliders can identify the nature of dark matter by analyzing specific processes and distributions, using polarized beams to enhance detection and distinguish between scalar and right-handed neutrino dark matter models.

Contribution

It introduces a method to differentiate dark matter types at colliders using kinematic cuts and polarized beams, focusing on scalar and right-handed neutrino models.

Findings

Polarized beams significantly improve dark matter detection sensitivity.

Distinct distributions help identify the dark matter nature.

Statistical significance is notably increased with polarization.

Abstract

In this work, we consider the process $e^{+}+e^{-}\rightarrow b\bar{b}+\slashed{E}_{T}$, at the future electron-positron colliders such as the International Linear Collider and Compact Linear Collider, to look for the dark matter (DM) effect and identify its nature at two different center-of-mass energies $E_{c.m.}=500~\mathrm{GeV}~and~1~\mathrm{TeV}$. For this purpose, we take two extensions of the standard model, in which the DM could be a real scalar or a heavy right-handed neutrino (RHN) similar to many models motivated by neutrino mass. In the latter extension, the charged leptons are coupled to the RHNs via a lepton flavor violating interaction that involves a charged singlet scalar. After discussing different constraints, we define a set of kinematical cuts that suppress the background, and generate different distributions that are useful in identifying the DM nature. The use of polarized beams (like the polarization $P(e^{-},e^{+})=\left[+0.8,-0.3\right]$ at the International Linear Collider) makes the signal detection easier and the DM identification more clear, where the statistical significance gets enhanced by twice (five times) for scalar (RHN) DM.