Search for a solar relaxion halo with the Global Network of Optical Magnetometers for Exotic physics (GNOME)

The relaxion is a hypothetical ultralight boson proposed to solve the hierarchy problem [Graham, Kaplan, and Rajendran, Phys. Rev. Lett. 115, 221801 (2015)]. Relaxions may comprise the majority of dark matter, and could collect in a halo trapped by the gravitational potential of the Earth or Sun [Banerjee et al., Communications Phys. 3, 1 (2020)]. The relaxion field interacts with atomic spins and would generate an oscillating signal detectable with atomic magnetometers, such as those comprising the Global Network of Optical Magnetometers for Exotic physics [GNOME, see Afach et al., Physics of the Dark Universe 22, 162 (2018)]. We present preliminary results of a search for a solar relaxion halo using GNOME data.