The Expected Signal Response of Neutron-Induced Migdal Effect in the LZ Experiment

The Migdal effect is an atomic process in which electrons are excited or ionized due to the perturbation of the electron cloud from a recoiling nucleus. In noble-liquid direct-detection dark matter experiments, this can be utilized to improve sensitivity to low-mass dark matter through the elevated signal response of the primary nuclear recoil (NR) due to the secondary electronic recoil (ER) of the Migdal effect. To test the current theoretical predictions of this pathology, the LUX-ZEPLIN (LZ) dark matter experiment has used a deuterium-deuterium (DD) neutron generator to produce a high rate of NRs via monoenergetic 2.45 MeV neutrons. We construct a model for the combined response of the secondary ERs with the standard NRs of neutron-xenon interactions in the LZ detector using GEANT and NEST. In this talk, I will review the signal model used for this rare-event search, and outline the relevant backgrounds in the Migdal effect region of interest.