Combined analysis of KamLAND and Borexino neutrino signals from Th and U decays in the Earth's interior

Journal Article · Mon Nov 01 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.82.093006· OSTI ID:21513046

Fogli, G L; Rotunno, A M ^[1]; Lisi, E ^[2]; Palazzo, A ^[3]

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1. Dipartimento Interateneo di Fisica 'Michelangelo Merlin', Via Amendola 173, 70126 Bari (Italy)
2. INFN, Sezione di Bari, Via Orabona 4, 70126, Bari (Italy)
3. AHEP Group, Institut de Fisica Corpuscular-C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, P.O. Box 22085, E46071 Valencia (Spain)

The KamLAND and Borexino experiments have detected electron antineutrinos produced in the decay chains of natural thorium and uranium (Th and U geoneutrinos). We analyze the energy spectra of current geoneutrino data in combination with solar and long-baseline reactor neutrino data, with marginalized three-neutrino oscillation parameters. We consider the case with unconstrained Th and U event rates in KamLAND and Borexino, as well as cases with fewer degrees of freedom, as obtained by successively assuming for both experiments a common Th/U ratio, a common scaling of Th+U event rates, and a chondritic Th/U value. In combination, KamLAND and Borexino can reject the null hypothesis (no geoneutrino signal) at 5{sigma}. Interesting bounds or indications emerge on the Th+U geoneutrino rates and on the Th/U ratio, in broad agreement with typical Earth model expectations. Conversely, the results disfavor the hypothesis of a georeactor in the Earth's core, if its power exceeds a few TW. The interplay of KamLAND and Borexino geoneutrino data is highlighted.

• OSTI ID: 21513046
• Journal Information: Physical Review. D, Particles Fields, Vol. 82, Issue 9; Other Information: DOI: 10.1103/PhysRevD.82.093006; (c) 2010 American Institute of Physics; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
DEGREES OF FREEDOM
EARTH CORE
ELECTRON ANTINEUTRINOS
ENERGY SPECTRA
HYPOTHESIS
NEUTRINO OSCILLATION
NUCLEAR DECAY
SCALING
THORIUM
URANIUM
ACTINIDES
ANTILEPTONS
ANTIMATTER
ANTINEUTRINOS
ANTIPARTICLES
DECAY
ELECTRON NEUTRINOS
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
LEPTONS
MASSLESS PARTICLES
MATTER
METALS
NEUTRINOS
SPECTRA