Enhanced Low-Temperature Light Detectors for Neutrino Physics – CryoLux

Neutrinos are subatomic particles with unique properties that challenge the predictions of the Standard Model of particle physics. The discovery of neutrino flavor oscillations and, indirectly, of neutrino masses allows for the existence of a nuclear transition known as neutrinoless double beta decay (0?2ß), not foreseen by the Standard Model. The observation of this very rare process, which violates lepton number conservation, would be of paramount importance in particle physics and cosmology, as it would fix the absolute neutrino mass scale and the Majorana nature of neutrino, and could explain the observed matter-antimatter asymmetry in the Universe.
CUPID is one of the most promising next generation 0?2ß experiments, studying the promising candidate 100Mo. It will consist of approximately 1600 scintillating bolometers based on Li2MoO4 crystals, to be operated at 20 mK within a cryostat located in the Gran Sasso Underground Laboratory (Italy). Each scintillating bolometer will provide a heat signal – measuring the energy of 0?2ß events – and a scintillation signal via an auxiliary light detector – crucial for background rejection.
CryoLux will be developed within the framework of CUPID. It will play a pivotal role in the construction of CUPID and lay the foundation for its next phase, CUPID-1T. The key innovation introduced by CryoLux and the core of its research program is the full development and optimization of an advanced type of light detector, based on the Neganov-Trofimov-Luke effect. This device will effectively reject the currently most significant background in CUPID: the random coincidence events resulting from ordinary two-neutrino double beta decay. CryoLux light detectors will allow CUPID to reach its sensitivity goals and, thanks to further advanced developments, will help to achieve almost zero background at an exposure scale of 10 ton x year in CUPID-1T, leading to a deep exploration of the normal ordering region in the neutrino mass pattern.