A method to define the energy threshold depending on noise level for rare events searches

Solid state detectors and cryogenic detectors are widely employed in rare event searches, such as direct Dark Matter detection or Coherent Neutrino Nucleus Scattering experiments. The excellent sensitivity and, consequently, their low energy thresholds are among the most appealing features of such detectors. In this paper we discuss a method based on the optimum filtering technique to quantify the lowest trigger threshold achievable as a function of the acceptable amount of noise events, given that the entire raw data stream from the detector is available.