Neutrino oscillations have led to exciting discoveries in the past decades and are still a vibrant field of research. Next-generation experiments will provide precise measurements of the oscillation parameters: an unprecedented control of the systematic uncertainties is thus required. This thesis will address both reconstruction of neutrino interactions in an oscillation experiments and the study of systematics.
The Deep Underground Neutrino Experiment (DUNE) is currently being constructed in the US. A neutrino beam produced at the Fermilab accelerator complex will be measured by a Near Detector on-site and Far Detectors located at SURF, in South Dakota, at a distance of 1300 km. This long baseline allows to disentangle the effect on the neutrino oscillation probabilities of two parameters that are still unknown: the so-called mass ordering (which of the 3 mass eigenstates is the heaviest) and the violation of the CP symmetry in the leptonic sector (possibly related to matter-antimatter asymmetry in the Universe). The Far Detectors modules will be gigantic Liquid Argon Time Projection Chambers (LArTPCs) providing excellent reconstruction of the neutrino interactions. Prototypes of these sophisticated detectors have been operating at CERN to test the technical solution and the performance in view of the physics requirements for DUNE.
The first part of the thesis will be devoted to the development of reconstruction algorithms and their validation on ProtoDUNE data, taken with beams of known particle types and energies. In particular, the possible use of the scintillation light signal, as a complement to the ionisation charge, to improve the resolution on energy and position measurement, will be studied. Construction of the first FD module is expected to be completed by the end of 2029: if the schedule is kept, the candidate will have the opportunity to analyse the very first data of DUNE.
One of the principal systematic uncertainties on the measurement of neutrino oscillations in DUNE is the knowledge of the neutrino interaction cross-section. In order to constrain them with higher precision than current experiments, a new project is proposed: nuSCOPE. It will use the neutrinos produced by the SPS accelerator complex at CERN to measure their interaction cross-sections with percent precision, relying on the novel techniques of beam monitoring and tagging. The second part of the thesis will focus on applying the reconstruction algorithms developed in ProtoDUNE to the LArTPC detector in the nuSCOPE simulation chain, to evaluate the actual sensitivity to the neutrino cross-sections.
The thesis work will be conducted at APC. Missions to CERN are foreseen to participate in the meetings of the two international collaborations, DUNE and nuSCOPE. The candidate will present her/his work in at least one international conference, in addition to national workshops and regular working group meetings.
Links:
DUNE https://www.dunescience.org
nuSCOPE https://nuscope.web.cern.ch