Low energy analysis techniques for CUORE

Abstract

CUORE is a tonne-scale cryogenic detector operating at the Laboratori Nazionali del Gran Sasso (LNGS) that uses tellurium dioxide bolometers to search for neutrinoless double-beta decay of 130 Te. CUORE is also suitable to search for low energy rare events such as solar axions or WIMP scattering, thanks to its ultra-low background and large target mass. However, to conduct such sensitive searches requires improving the energy threshold to 10 keV. In this paper, we describe the analysis techniques developed for the low energy analysis of CUORE-like detectors, using the data acquired from November 2013 to March 2015 by CUORE-0, a singletower prototype designed to validate the assembly procedure and new cleaning techniques of CUORE. We explain the energy threshold optimization, continuous monitoring of the trigger efficiency, data and event selection, and energy calibration at low energies in detail. We also present the low energy background spectrum of CUORE-0 below 60 keV. Finally, we report the sensitivity of CUORE to WIMP annual modulation using the CUORE-0 energy threshold and background, as well as an estimate of the uncertainty on the nuclear quenching factor from nuclear recoils inCUORE-0.

First Results from CUORE: A Search for Lepton Number Violation via 0νββ Decay of Te130Alduino1, Alessandria2, Alfonso3 et al. 2018Phys. Rev. Lett.Self Cite28572602View full textAdd to dashboardCite

“…A total of 984 of 988 channels are functioning. Thermal event pulses are identified by a software derivative trigger with channel-dependent thresholds ranging from 20 to a few hundred keV; we anticipate reducing these thresholds for future low-energy studies [44,45]. The rise and fall times of thermal pulses are on the order of 100 ms and 400 ms, respectively.…”

Search for Majorana neutrinos exploiting millikelvin cryogenics with CUORE

“…The 0νββ sensitivity and exposure that CUORE has attained demonstrate that the cryogenic calorimetric technique is scalable to the tonne-scale detector masses and multiyear live times necessary to be competitive in the current international 0νββ decay search program. The large accumulated exposure paired with the low energy thresholds of CUORE's calorimeters will also enable searches for other new physics in the low energy regime [49].…”

“…We set a common analysis threshold of 40 keV to guarantee that our trigger efficiency is above 90% for the majority (97%) of our detectors while also being low enough to reliably remove multi-Compton events from the ROI with the anti-coincidence cut. Our improved ability to detect low-energy events using this OT method also increases the efficiency with which we can reconstruct events that release energy in more than one calorimeter, improving our background reconstruction ability [49,53].…”

Status and Perspectives on Rare Decay Searches in Tellurium Isotopes

“…The data analysis procedure is described in detail in [70] and mostly follows the strategy adopted for CUORE-0 [96]. Recent improvements include a significant lowering of the detectors energy threshold thanks to the application of the optimum trigger algorithm based on the matched filter technique [98,99] and the introduction of a new methodology for pulse shape analysis with higher efficiencies [100]. The energy thresholds have a relevant role on the effectiveness of the anti-coincidence analysis.…”