Study of background from accidental coincidence signals in the PandaX-II experiment

Understand

The PandaX-II experiment employed a 580kg liquid xenon detector to search for the interactions between dark matter particles and the target xenon atoms.

• The accidental coincidences of isolated signals result in a dangerous background which mimic the signature of the dark matter.
• We performed a detailed study on the accidental coincidence background in PandaX-II, including the possible origin of the isolated signals, the background level and corresponding background suppression method.
• With a boosted-decision-tree algorithm, the accidental coincidence background is reduced by 70% in the dark matter signal region, thus the sensitivity of dark matter search at PandaX-II is improved.