Secular Equilibrium Assessment in a $\mathrm{CaWO}_4$ Target Crystal from the Dark Matter Experiment CRESST using Bayesian Likelihood Normalisation
physics.ins-det
/ Authors
G. Angloher, S. Banik, G. Benato, A. Bento, A. Bertolini, R. Breier, C. Bucci, J. Burkhart, L. Canonica, A. D'Addabbo
and 51 more authors
S. Di Lorenzo, L. Einfalt, A. Erb, F. v. Feilitzsch, N. Ferreiro Iachellini, S. Fichtinger, D. Fuchs, A. Fuss, A. Garai, V. M. Ghete, P. Gorla, S. Gupta, D. Hauff, M. Ješkovský, J. Jochum, M. Kaznacheeva, A. Kinast, H. Kluck, H. Kraus, A. Langenkämper, M. Mancuso, L. Marini, V. Mokina, A. Nilima
/ Abstract
CRESST is a leading direct detection sub-$\mathrm{GeVc}^{-2}$ dark matter experiment. During its second phase, cryogenic bolometers were used to detect nuclear recoils off the $\mathrm{CaWO}_4$ target crystal nuclei. The previously established electromagnetic background model relies on secular equilibrium (SE) assumptions. In this work, a validation of SE is attempted by comparing two likelihood-based normalisation results using a recently developed spectral template normalisation method based on Bayesian likelihood. We find deviations from SE; further investigations are necessary to determine their origin.