Crosstalk Characterization for the LEGEND-200 Experiment*

The discovery of the lepton-number-violating neutrinoless double-beta decay (0νββ) process would determine if the neutrino mass is Majorana or Dirac in nature, give insight to the origin of neutrino mass, and provide an explanation for possible leptogenesis processes in the early universe.  Searches for 0νββ using ⁷⁶Ge-enriched High-Purity Germanium (HPGe) detectors have proven to be very successful, with the previous-generation experiments the MAJORANA DEMONSTRATOR (MJD) and GERDA demonstrating the best energy resolution and lowest backgrounds in the field, respectively. This program is rapidly advancing, with the present-generation LEGEND-200 experiment now successfully taking data.

 

Ultra-precise experiments such as these require the ability to reconstruct the energy deposition and topology of the particle interactions in the ⁷⁶Ge detectors to an extreme degree in order to recover a potential 0νββ decay, and any effects which could affect the energy collected by a detector must be understood and corrected. An example of one such effect is the presence of crosstalk in complex detector electronic circuit systems, whereby a transient energy signal present in one subsystem (e.g. a pulse generated by a particle interactionin an individual germanium detector channel) can bleed over to another subsystem, resulting in an incorrect energy being recorded for the event. The LEGEND-200 experiment is one such complex electronics system, consisting of an array of over 100 individual ⁷⁶Ge semiconductor detectors, a liquid argon (Lar) instrumentation system with dozens of silicon photomultiplier (SiPM) detectors, and a muon veto system with dozens of photomultiplier (PMT) detectors. This talk will present the techniques and algorithms being designed and implemented in the LEGEND-200 analysis framework to quantify and correct for these effects in the LEGEND-200 experiment.