DUNE atmospheric neutrinos: Earth tomography

Abstract

In this paper we show that the DUNE experiment can measure the Earth’s density profile by analyzing atmospheric neutrino oscillations. The crucial feature that enables such measurement is the detailed event reconstruction capability of liquid argon time projection chambers. This allows for studying the sub-GeV atmospheric neutrino component, which bears a rich oscillation phenomenology, strongly dependent on the matter potential sourced by the Earth. We provide a pedagogical discussion of the MSW and parametric resonances and their role in measuring the core and mantle densities. By performing a detailed simulation, accounting for particle reconstruction at DUNE, nuclear physics effects relevant to neutrino-argon interactions and several uncertainties on the atmospheric neutrino flux, we manage to obtain a robust estimate of DUNE’s sensitivity to the Earth matter profile. We find that DUNE can measure the total mass of the Earth at 9.3% precision with an exposure of 400 kton-year. By accounting for previous measurements of the total mass and moment of inertia of the Earth, the core, lower mantle and upper mantle densities can be determined with 9%, 14% and 22% precision, respectively, for the same exposure. Finally, for a low exposure run of 60 kton-year, which would correspond to two far detectors running for three years, we have found that the core density could be measured by DUNE at ∼ 30% precision.

Unveiling the outer core composition with neutrino oscillation tomography

“…The impact of systematic uncertainties related to the oscillation parameters and to the normalization, shape and flavour content of the atmospheric neutrino flux have been discussed more extensively in some other recent studies, both for ORCA-like (Rott et al, 2015;Winter 2016;Bourret and Van Elewyck, 2019;Capozzi and Petcov, 2022;D'Olivo Saez et al, 2022) and DUNE-like (Kelly et al, 2022) detectors, and shown to have a limited to moderate impact on tomographic measurements. In the specific case of the measurement of the core composition which is our focus here, we benefit from the fact that such systematic effects can be mitigated and controlled by exploiting the sample of neutrino events that only traverse the mantle (and not the core).…”

“…The DUNE-like model (Abi et al, 2020a;2020c;Kelly et al, 2022) accounts for the superior resolution and reconstruction capabilities of the Liquid Argon detection technique, at the cost of a much smaller instrumented volume. At the other extreme, the ORCA-like model (Adrian-Martinez et al, 2016;Aiello et al, 2022) reflects the higher detection threshold and degraded reconstruction performances that result from a sparsely instrumented -although larger -volume.…”

“…While this method of Earth tomography has been conceptually explored in different contexts since the 1980s [see, e.g., Ermilova et al (1986); Nicolaidis (1988); Nicolaidis et al (1991); Ohlsson and Winter (2001); Ohlsson and Winter (2002); Lindner et al (2003); Winter (2006) and references therein], only now does the upcoming generation of atmospheric neutrino detectors provide a concrete opportunity to evaluate its capability of probing the density and/or composition of the deep Earth. Oscillation tomography with atmospheric neutrinos has been recently discussed by several authors (Rott et al, 2015;Winter 2016;Bourret et al, 2018;Bourret and Van Elewyck, 2019;D'Olivo et al, 2020;Kumar and Agarwalla, 2021;Denton and Pestes, 2021;Kelly et al, 2022;Capozzi and Petcov, 2022;D'Olivo Saez et al, 2022), with a variety of approaches in the treatment of the neutrino signal and in the targeted geophysical observables. In this study, we propose to re-examine the relevance and potential of this method for the characterization of the Earth's core composition, with a specific focus on its capacity to identify and quantify the presence of Hydrogen in the core.…”

Locating the core-mantle boundary using oscillations of atmospheric neutrinos

“…The possibility of probing the internal structure of Earth using these density-dependent matter effects is known as "neutrino oscillation tomography". These studies have been performed using man-made neutrino beams [61][62][63][64][65][66][67][68][69][70][71], supernova neutrinos [72,73], solar neutrinos [72,[74][75][76][77][78][79], and atmospheric neutrinos [80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95]. In the sub-GeV and multi-GeV energy ranges, atmospheric neutrinos are the best source of neutrinos to probe the internal structure of Earth because they have access to a wide range of baselines starting from about 15 km to 12750 km which cover all the layers of Earth.…”

Measuring Oscillations with A Million Atmospheric Neutrinos

“…Beyond the MSW effect, at energies around 1 GeV, the oscillation is enhanced for some trajectories crossing Earth's core and mantle due to the matter distribution, the so-called parametric resonance [49,[138][139][140][141][142][143][144][145][146][147][148]. Both types of resonance happen for neutrinos if the mass ordering is normal and for anti-neutrinos ∆ 21 that goes to zero, so that δ CP has a larger impact in the neutrino evolution at sub-GeV energies and for Earth-size baselines.…”