Experimental study reveals enhanced electronic recoil rejection in the LUX-ZEPLIN detector, indicating improved sensitivity for detecting weakly interacting massive particles.
Key Points
To evaluate and optimize pulse shape discrimination and two-factor discrimination techniques for electronic recoil background suppression in the LUX-ZEPLIN dark matter detector.
Developed an analysis framework to reconstruct single-photon arrival times from scintillation pulse shapes.
Optimized a photon-timing tail fraction discriminator using LUX-ZEPLIN calibration datasets.
Combined pulse shape discrimination with the charge-to-light ratio into a two-factor discrimination framework and evaluated it on WS2024 run data.
The photon-timing tail fraction discriminator achieved electronic recoil leakage as low as 15%, reducing further to approximately 5% for xenon-124 double electron capture events.
Two-factor discrimination reduced the false positive rate by up to a factor of two for large scintillation pulses compared to the standard charge-to-light method.