Detection capability of the Migdal effect for argon and xenon nuclei with position-sensitive gaseous detectors

Abstract

Migdal effect is attracting interests because of the potential to enhance the sensitivities of direct dark matter searches to the low mass region. In spite of its great importance, the Migdal effect has not been experimentally observed yet. A realistic experimental approach towards the first observation of the Migdal effect in the neutron scattering was studied with Monte Carlo simulations. In this study, potential background rate was studied together with the event rate of the Migdal effect by a neutron source. It was found that a table-top sized ~ (30cm)3 position-sensitive gaseous detector filled with argon or xenon target gas can detect characteristic signatures of the Migdal effect with sufficient rates (O(102 ~ 103) events/day). A simulation result of a simple experimental set-up showed two significant background sources, namely the intrinsic neutrons and the neutron induced gamma-rays. It is found that the intrinsic neutron background rate for the argon gas is acceptable level and some future study for the reduction of the gamma-rays from the laboratory would make the observation of the Migdal effect possible. The background for the xenon gas, on the other hand, is found to be much more serious than for the argon gas. Future works on the isotope separation as well as the reduction of the gamma-rays from the detector and laboratory will be needed before the Migdal effect observation for xenon gas case.

DarkELF: A python package for dark matter scattering in dielectric targets

“…The Migdal effect [21,22] refers to the pro-cess where the atom shakes off one or more electrons immediately after being struck by an external probe, which in our case is the DM. This process was studied extensively in the context of DM scattering off atomic targets [10][11][12][23][24][25][26][27][28][29][30][31][32] and estimates were obtained for semiconductor targets [26,32].…”

“…One way this could happen is if the nucleus "shakes-off" an electron during the initial hard recoil [10][11][12]. This is known as the Migdal effect [21,22], and has been applied extensively to DM scattering off atomic targets [23][24][25][26][27][28][29][30][31][32]. Refs.…”

Revisiting the Fermionic Dark Matter Absorption on Electron Target

“…More importantly, the invisible decay mode dominates over the visible ones by at least 4 orders. This can be seen by comparing (28) with (31), and ( 34) with (35). If a significant amount of the DM decays invisibly to inject its energy into relativistic degrees of freedom, the expansion history of the Universe can receive sizable modifications.…”

“…There are several ways of improving the detection of light DM. For nuclear recoil, the detection threshold can be lowered by using Germanium point-contact detector [18], bolometer [19,20], nuclear bremsstrahlung [21,22], and Migdal effect [22][23][24][25][26][27][28][29][30][31][32][33]. Or one may replace the nuclear recoil by electron recoil.…”

Observing the Migdal effect from nuclear recoils of neutral particles with liquid xenon and argon detectors

“…In this section we detail the calculation of the Migdal effect from elastic scattering of neutrons from xenon and argon nuclei as well as the intrinsic backgrounds. This has been previously explored in [23], where it was proposed to use gaseous detectors and neutrons of 565 keV energy. Our approach is different in two important ways.…”