CUORE sensitivity to $$0\nu \beta \beta $$ decay

Abstract

We report a study of the CUORE sensitivity to neutrinoless double beta (0νββ) decay. We used a Bayesian analysis based on a toy Monte Carlo (MC) approach to extract the exclusion sensitivity to the 0νββ decay half-life (T 0ν 1/2 ) at 90% credibility interval (CI) -i.e. the interval containing the true value of T 0ν 1/2 with 90% probability -and the 3 σ discovery sensitivity. We consider various background levels and energy resolutions, and describe the influence of the data division in subsets with different background levels. If the background level and the energy resolution meet the expectation, CUORE will reach a 90% CI exclusion sensitivity of 2 · 10 25 year with 3 months, and 9 · 10 25 year with 5 years of live time. Under the same conditions, the discovery sensitivity after 3 months and 5 years will be 7 · 10 24 year and 4 · 10 25 year, respectively.

Neutrino predictions from a left-right symmetric flavored extension of the standard model

“…The experimental sensitivity of 0νββ searches is expected to improve in the near future. For our model, the predicted 0νββ decay rates may be tested by the next-generation bolometric CUORE experiment [69], as well as the next-to-next-generation ton-scale 0νββ-decay experiments [63,[70][71][72].…”

Background model of the CUPID-0 experiment

“…However, the energy resolution is only one of the parameters that concur to determine the sensitivity of an experiment for the search of 0νββ decay. Others are the number of isotopes under study, the live time, the detection efficiency and the background rate in the energy region of interest (ROI) [3]. The goal of the background model described in this work is to identify the sources of the CUPID-0 background and evaluate their contribution to the ROI around the 82 Se 0νββ Q-value (2997.9±0.3 keV [4]).…”

“…Their counting rate in the ROI bkg has a maximum variation of ∼30% when fitting with the reduced list (that does not include 10 µm surface contaminations of Crystals) and when performing the tests number 2 and 3.The systematic uncertainties affecting the ROI bkg counting rate due to Reflectors and Holder contaminations are investigated through tests number 3, 4, and 5. The bulk /deep surface contaminations in Reflectors produce a continuum of degraded α that allows to obtain a good fit to the M 1α spectrum in the[2][3][4] MeV range. Since 232 Th in Reflectors is constrained by a prior which makes negligible its contribution, 226 Ra-210 Pb and 210 Pb-206 Pb are the only reflector sources which are left free to fit this continuum.…”

The CUORE cryostat: An infrastructure for rare event searches at millikelvin temperatures

“…Assays of the CUORE OFE copper have placed upper limits on the 232 Th and 238 U activity at < 6.5 · 10 −5 Bq kg −1 and < 5.4 · 10 −5 Bq kg −1 , respectively. 4 The MC vessel, MC plate, and the TSP are made of electrolytic tough pitch copper, referred to here as NOSV copper [20]. This is the same copper used to produce 4 A detailed description of the vessel production and machining can be found in Ref.…”

“…4 The MC vessel, MC plate, and the TSP are made of electrolytic tough pitch copper, referred to here as NOSV copper [20]. This is the same copper used to produce 4 A detailed description of the vessel production and machining can be found in Ref. [19], where special attention is paid to the description of the welding techniques employed to minimize radioactive contamination during welding.…”