Background studies in neutrinoless double beta decay and dark matter searches

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A90263%2F24%3A00381716" target="_blank" >RIV/68407700:90263/24:00381716 - isvavai.cz</a>

Result on the web

<a href="https://hal.science/tel-04633827" target="_blank" >https://hal.science/tel-04633827</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Background studies in neutrinoless double beta decay and dark matter searches

Original language description

Neutrinoless double beta decay (0νββ) and dark matter searches poses an experimental challenge as in both searches the hypothetical signals are expected to happen at very low rates, competing with the background from natural radioactivity that populates the region of interest. However, the reward is worth the effort. If neutrinoless double beta decay is observed, it would demonstrate that neutrino is the only fermion to be a Majorana particle, and thus, that lepton number is non conserved, opening the door to physics beyond the Standard Model. The dark matter paradigm sets its basis on cosmology and astrophysical observations, rather than on particle physics. Both searches need to understand and to reduce the backgrounds to extremely low levels. The work presented in this HDR is dedicated to such background studies. First, I describe the backgrounds and the methods commonly used to assay radioactive contaminations and I present the development of two ultra-low background HPGe gamma-ray spectrometers, today in operation at the Laboratoire Souterrain de Modane. One of them is among the most sensitive gamma-ray Ge spectrometers world-wide. I describe also the BiPo-3 detector, developed in the framework of the SuperNEMO 0νββ experiment, which was dedicated to the measurement of the surface contaminations of the 0νββ source foils. CUORE is at present the largest 0νββ bolometric detector. The CUORE background is dominated by alphas from the surfaces facing the crystals. Thanks to scintillating bolometers, the next generation experiment CUPID will reduce the background by two orders of magnitude. The performance of this technique was demonstrated in the CUPID-Mo experiment. I describe a detailed model of the CUPID-Mo backgrounds, which is able to describe well the features of the experimental data and enables studies of the 2νββ decay and other processes with high precision.. Finally, I present the estimated backgrounds for CUPID. They confirm that CUPID will be able to reach a sensitivity for discovery of neutrinoless double beta decay of T1/2 >10^27 years and effective Majorana mass < 12 – 20 meV.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

10304 - Nuclear physics

Project

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Continuities

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Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů