The Fast Stochastic Matching Pursuit for Neutrino and Dark Matter Experiments

Photomultiplier tubes (PMT) are widely deployed at neutrino and dark matterexperiments for photon counting. When multiple photons hit a PMT consecutively,their photo-electron (PE) pulses pile up to hinder the precise measurements ofthe count and timings. We introduce Fast Stochastic Matching Pursuit (FSMP) toanalyze the PMT signal waveforms into individual PEs with the strategy ofreversible-jump Markov-chain Monte Carlo. We demonstrate that FSMP improves theenergy and time resolution of PMT-based experiments, gains acceleration on GPUsand is extensible to microchannel-plate (MCP) PMTs with jumbo-charge outputs.In the condition of our laboratory characterization of 8-inch MCP-PMTs, FSMPimproves the energy resolution by up to 12waveform integration.