Bounds on Dipole Moments of hidden Dark Matter through kinetic mixing

TL;DR

This paper derives bounds on the electric and magnetic dipole moments of hidden sector dark matter particles interacting via kinetic mixing, using direct detection data and constraining model parameters relevant for collider searches.

Contribution

It provides new bounds on dark matter dipole moments and kinetic mixing parameters, linking direct detection results with hidden sector gauge boson mass constraints.

Findings

Bounds on magnetic dipole moment: ~2×10^{-8} μ_B

Bounds on electric dipole moment: ~3.3×10^{-23} e·cm

Constraints on kinetic mixing parameter and hidden gauge boson mass

Abstract

The existence of dark sectors, consisting of weakly-coupled particles that do not interact with the known Standard Model forces, is theoretically and phenomenologically motivated. The hidden particles are candidates for Dark Matter and can interact with photon through electric dipole moment (EDM) and magnetic dipole moment (MDM). We investigate the possibility a hidden sector's Dark Matter which is charged under a hidden $U(1)_X$ gauge symmetry can interact with photon at loop level. We evaluate the scattering cross section of hidden Dirac fermion with nuclei and set bounds for dipole moment. Using the results of the XENON1T experiment for direct detection of Dark Matter, we get bounds of electromagnetic dipole moment $(\mu_\chi)$ for mass $m_\chi=100$ GeV : $ 1.93448 \times 10^{-8}\mu_B \leq \mu_\chi \leq 1.9496 \times 10^{-8}\mu_B$ and electric dipole moment $(d_\chi): 3.3204 \times 10^{-23}e\mbox{.}cm \leq d_\chi \leq 3.3464 \times 10^{-23}e\mbox{.}cm$. Using the condition of the existence of dipole moment we constraint the kinetic mixing parameter $ 3\times 10^{-3} \leq \epsilon \leq 10^{-2}$ and the mass of the hidden $U(1)_X$ gauge boson to be in the range of 5 GeV $\leq m_X \leq$ 9 GeV. Our results complement previous works and are within detection capability of LHC.