Speaker
Description
The BeEST experiment uses Superconducting Tunnel Junction (STJ) particle
detectors to search for sub-MeV neutrino masses states by precisely measuring the daughter recoil energy following the Electron Capture (EC) decay of 7Be. In order to study systematic errors of the detector, we have estimated the Electron Shaking Probability (ESP) in the L-capture peak of the 7Be nuclear EC decay spectra. This probability has a purely physical origin, then its value must be the same for all pixels in the detector. Its quantification allows us to understand systematic errors, improve the calibration method, data processing, efficiency of future pixels, and the sensitivity of the detector. This poster presents the mathematical modeling, fitting process, and analysis method used to estimate the ESP in the 7Be nuclear EC decay spectrum, and the most recent result achieved by the BeEST collaboration, which is consistent with the previous bibliography.
The BeEST experiment is supported by the DOE-SC Office of Nuclear Physics, Lawrence Livermore National Laboratory, TRIUMF, and the European Metrology Programme for Innovation and Research (EMPIR).
