Pith. sign in

REVIEW 3 cited by

Experimental evidence of neutrinos produced in the CNO fusion cycle in the Sun

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2006.15115 v2 pith:Z5SNTUJ2 submitted 2020-06-26 hep-ex astro-ph.IMastro-ph.SRphysics.ins-det

classification hep-exastro-ph.IMastro-ph.SRphysics.ins-det
keywords neutrinosfusioncyclesolardirectexperimentalhydrogenbeen
verification ladder T0 review T1 audit T2 compute T3 formal
0 comments
abstract

For most of their existence stars are fueled by the fusion of hydrogen into helium proceeding via two theoretically well understood processes, namely the $pp$ chain and the CNO cycle. Neutrinos emitted along such fusion processes in the solar core are the only direct probe of the deep interior of the star. A complete spectroscopy of neutrinos from the {\it pp} chain, producing about 99\% of the solar energy, has already been performed \cite{bib:Nature-2018}. Here, we report the direct observation, with a high statistical significance, of neutrinos produced in the CNO cycle in the Sun. This is the first experimental evidence of this process obtained with the unprecedentedly radio-pure large-volume liquid-scintillator Borexino detector located at the underground Laboratori Nazionali del Gran Sasso in Italy. The main difficulty of this experimental effort is to identify the excess of the few counts per day per 100 tonnes of target due to CNO neutrino interactions above the backgrounds. A novel method to constrain the rate of \bi contaminating the scintillator relies on the thermal stabilisation of the detector achieved over the past 5 years. In the CNO cycle, the hydrogen fusion is catalyzed by the carbon (C) - nitrogen (N) - oxygen (O) and thus its rate, as well as the flux of emitted CNO neutrinos, directly depends on the abundance of these elements in solar core. Therefore, this result paves the way to a direct measurement of the solar metallicity by CNO neutrinos. While this result quantifies the relative contribution of the CNO fusion in the Sun to be of the order of 1\%, this process is dominant in the energy production of massive stars. The occurrence of the primary mechanism for the stellar conversion of hydrogen into helium in the Universe has been proven.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 3 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. First Demonstration of a Hybrid Cherenkov and Scintillation Detector in a Proof-of-Principle Axion Search at a Beam Dump

    hep-ex 2026-07 conditional novelty 7.0 of 10

    First event-by-event Cherenkov separation from sub-MeV electrons in liquid argon enables a proof-of-principle ALP search excluding new parameter space despite no observed excess.

  2. Sensitivity of nEXO to $^{136}$Xe Charged-Current Interactions: Background-free Searches for Solar Neutrinos and Fermionic Dark Matter

    nucl-ex 2025-06 conditional novelty 6.0 of 10

    A new delayed-coincidence tag from 136Cs isomers could let the nEXO detector reject backgrounds down to 10^-9 and measure CNO solar neutrinos, the 7Be neutrino energy, and sub-MeV fermionic dark matter.

  3. Probing Dark Matter and Phantom Field Effects on Neutrino Oscillations around Black Holes

    hep-ph 2026-08 reject novelty 4.0 of 10

    For neutrinos deflected by a black hole embedded in phantom-field dark matter, the oscillation phase gains a logarithmic dark matter correction, while radially moving neutrinos see no net gravity effect.

Pith tools