Neutrino physics at ESS using coherent elastic neutrino-nucleus scattering.

Coherent Elastic Neutrino-Nucleus Scattering (CEνNS) is a recently demonstrated novel process of neutrino interaction.

It provides numerous avenues to advance our sensitivity to new nuclear and particle physics beyond the Standard Model while simultaneously allowing a dramatic miniaturization of otherwise massive neutrino detectors, opening up the possibility of technological applications.

Both the supervisor and the partner organization host, along a number of collaborators, recently proposed to use the neutrino flux from the upcoming European Spallation Source (ESS) for a definitive exploration of all phenomenological opportunities provided by CEνNS.The proposal includes a variety of detection techniques to evaluate such a process including the use high-pressure gaseous xenon (HPGXe) chambers and cryogenic undoped CsI scintillator crystals.

For reasons of nuclear structure, CsI and Xe detectors are identical in their response to CEνNS. However, the technologies and their expected systematics are fully different. Simultaneous use at the ESS will therefore provide robust confirmation for any possible signatures of new physics.

During the outgoing phase (OP) the researcher will take part in the development and characterization of a 31.5 Kg cryogenic undoped CsI array which will be later deployed in ESS.

While HPGXe detectors are a mature technology, their response to nuclear recoils in the energy range of CEνNS is unknown.

Characterizing the response in such range is one of the main goals of this proposal and the methodology to do so will be developed during the OP.

In the incoming phase, the researcher will implement the techniques developed during the OP in a small HPGXe chamber currently being built in DIPC.

The studies will be repeated in a larger demonstrator in which he'll take a leading role in the design and deployment.Finally, the researcher will evaluate, through simulation and on-site measurements, the neutron background for CEνNS searches at ESS.