Neutrino oscillations and earth tomography with KM3NeT-ORCA

• Main Author: Bourret, Simon
• Other Authors: AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Sorbonne Paris Cité, Véronique Van Elewyck, Édouard Kaminski
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: HAL CCSD 2018
• Subjects: Oscillations Flavour; Neutrino atmospheric; Matter; Earth; Mass; Neutrino mass hierarchy; Oscillations de saveur; Neutrino atmosphérique; Matière; Terre; Masse; Hiérarchie de masse des neutrinos; [PHYS.PHYS]Physics [physics]/Physics [physics]; Orca
• Online Access: https://tel.archives-ouvertes.fr/tel-02491394; https://tel.archives-ouvertes.fr/tel-02491394/document; https://tel.archives-ouvertes.fr/tel-02491394/file/BOURRET_Simon_1_complete_20181130.pdf

Neutrino flavour oscillations, discovered at the turn of the 21st century, currently provide the most direct window on physics beyond the Standard Model. The KM3NeT collaboration has started the construction of a megaton-scale Cherenkov neutrino detector deep underwater in the Mediterranean: ORCA (Oscillation Research with Cosmics in the Abyss). ORCA's main goal will be the determination of the neutrino mass hierarchy, a major unknown in the current understanding of neutrino oscillations, via the detection of large samples of atmospheric neutrinos crossing the Earth and the analysis of their flavour oscillations. These oscillations are enhanced by matter effects, sensitive to the electron density along the neutrino paths. Beyond the neutrino mass hierarchy and the measurement of atmospheric oscillation parameters, this will allow ORCA to measure the electron density of the deep Earth, and possibly provide constraints on the chemical composition of its innermost layers. This thesis presents a new study, undertaken within the KM3NeT collaboration, of the sensitivity of ORCA to the determination of the neutrino mass hierarchy, oscillation parameters, and the electron density in the outer core and lower mantle of the Earth. The focus is given to the development of a new analysis methodology intended to account for detector effects as precisely as possible by the use of a Monte Carlo based correlated model of detector response. Statistical methods and systematic uncertainties are also addressed in some detail. The methodology allows for a preliminary exploration of the potential of improved analysis strategies. Sensitivity studies show that ORCA is expected to achieve a median sensitivity to the NMH determination at the level of 3 sigma or better after a few years of operation, depending on the true hierarchy and true value of the oscillation parameters. Competitive performance for the measurement of atmospheric oscillation parameters is also expected. Assuming a normal mass hierarchy, the electron density can be ...