Absorption and oscillation tomography of the deep Earth with KM3NeT and future atmospheric neutrino detectors

• Main Author: Maderer, Lukas
• Other Authors: APC - Neutrinos, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Paris Cité, Edoaurd Kaminsiki
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: HAL CCSD 2022
• Subjects: neutrino; oscillation; absorption; Earth; matter; LLSVP; Terre; matière; [PHYS]Physics [physics]; Orca
• Online Access: https://theses.hal.science/tel-03859695; https://theses.hal.science/tel-03859695/document; https://theses.hal.science/tel-03859695/file/PhD_Thesis_final.pdf

Structure and composition of the deep Earth are constrained by seismic methods and geochemical models based on primitive meteorites. These leave some questions unsolved, such as the exact composition of the outer core or the nature of seismic anomalies at the core/mantle boundary (LLSVP). Neutrinos are neutral elementary particles that only interact with matter by the weak force and are thus able to cover large distances even through dense media such as the Earth, opening a new window to study our planet's interior. By studying absorption of atmospheric neutrinos>30TeV, absorption tomography allows to draw conclusions about the average matter density along the neutrino path. Furthermore, at energies of a few GeV, oscillation tomography exploits the fact that neutrino avour oscillations are affected by the electron density along the neutrino path, an observable connected to both the matter density and chemical composition of the traversed media. The first studies in this thesis are performed for the two water-Cherenkov detectors ARCA and ORCA, currently being built in the Mediterranean Sea as part of the KM3NeT infrastructure. The detector response is modelled using Monte Carlo simulations developed within the KM3NeT Collaboration. Absorption tomography with ARCA can resolve the average radial density profile of the Earth with a clear separation of core and mantle. The precision from studying atmospheric neutrinos alone appears insufficient to study finer structures. Improvements could come by exploiting the high energy astrophysical neutrino flux, as detected by IceCube. From oscillation tomography with ORCA, density variations compared to PREM can be constrained with a respective precision of +24%/-32% for the inner core and ~5% for the lower mantle, with 10 yr of ORCA data. In the same timescale, ORCA could constrain the density variations of large seismic anomalies in the deep mantle to +24%/-21 %. The sensitivity to the proton-to-nucleon ratio (Z/A) in the outer core was found to be ~5 %. The second part ...