Pulse Amplitude Reconstruction in the LDMX Hadronic Calorimeter Readout

Abstract: The universe shows signs of containing some invisible matter, known as dark matter. There are many possible constituents for dark matter, one such being light dark matter which would interact with ordinary matter through a new mediator force and have masses in the range of a few MeV to GeV. The light dark matter mass range is largely unexplored experimentally. The Light Dark Matter eXperiment, LDMX, is a proposed experiment using an electron beam incident on a tungsten target to produce dark matter. LDMX consists of trackers and calorimeters capable of fully reconstructing both the incident and recoil electrons’ momentum and energy. The signature for dark matter production is a scattered electron with missing momentum. The hadronic calorimeter is responsible for detecting neutral particles, vetoing events that would otherwise mimic the signal signature in the trackers and electromagnetic calorimeter. This project focuses on finding and testing a function reconstructing the amplitude of the pulses registered in the hadronic calorimeter’s read-out electronics, using precise calibration pulses. The calibration pulses are sampled every 25 ns leading to discrete datapoints with the possibility of missing the peak. A function reconstructing the pulse amplitude was successfully attained and the results showed an ability to accurately extract the amplitude of pulses of a sufficient width.