A likelihood framework for cryogenic scintillating calorimeters used in the CRESST dark matter search

Abstract

Cryogenic scintillating calorimeters are ultrasensitive particle detectors for rare event searches, particularly for the search for dark matter and the measurement of neutrino properties. These detectors are made from scintillating target crystals generating two signals for each particle interaction. The phonon (heat) signal precisely measures the deposited energy independent of the type of interacting particle. The scintillation light signal yields particle discrimination on an event-by-event basis. This paper presents a likelihood framework modeling backgrounds and a potential dark matter signal in the two-dimensional plane spanned by phonon and scintillation light energies. We apply the framework to data from CaWO${}_4$-based detectors operated in the CRESST dark matter search. For the first time, a single likelihood framework is used in CRESST to model the data and extract results on dark matter in one step by using a profile likelihood ratio test. Our framework simultaneously fits (neutron) calibration data and physics (background) data and allows combining data from multiple detectors. Although tailored to CaWO${}_4$-targets and the CRESST experiment, the framework can easily be expanded to other materials and experiments using scintillating cryogenic calorimeters for dark matter search and neutrino physics.

18 pages, 11 figures, additional figures and data in ancillary files (on arXiv or at journal reference)

References in corpus (15)

• Asymptotic formulae for likelihood-based tests of new physics
• Results from 730 kg days of the CRESST-II Dark Matter Search
• First results from the CRESST-III low-mass dark matter program
• Results on light dark matter particles with a low-threshold CRESST-II detector
• Finding an Upper Limit in the Presence of Unknown Background
• Results on low mass WIMPs using an upgraded CRESST-II detector
• Model Independent Form Factors for Spin Independent Neutralino-Nucleon Scattering from Elastic Electron Scattering Data
• EXCESS workshop: Descriptions of rising low-energy spectra
• The COSINUS project - perspectives of a NaI scintillating calorimeter for dark matter search
• Gram-scale cryogenic calorimeters for rare-event searches
• Effects of galactic dark halo rotation on WIMP direct detection
• Energy-Dependent Light Quenching in CaWO${}_4$ Crystals at mK Temperatures
• Geant4-based electromagnetic background model for the CRESST dark matter experiment
• Latest observations on the low energy excess in CRESST-III
• Scintillator Non-Proportionality and Gamma Quenching in CaWO4

Cited by in corpus (1)

• Constraints on self-interaction cross-sections of dark matter in universal bound states from direct detection