Measurement of neutron production in atmospheric neutrino interactions at the Sudbury Neutrino Observatory

Abstract

Neutron production in GeV-scale neutrino interactions is a poorly studied process. We have measured the neutron multiplicities in atmospheric neutrino interactions in the Sudbury Neutrino Observatory experiment and compared them to the prediction of a Monte Carlo simulation using GENIE and a minimally modified version of GEANT4. We analyzed 837 days of exposure corresponding to Phase I, using pure heavy water, and Phase II, using a mixture of Cl in heavy water. Neutrons produced in atmospheric neutrino interactions were identified with an efficiency of $15.3\%$ and $44.3\%$, for Phase I and II respectively. The neutron production is measured as a function of the visible energy of the neutrino interaction and, for charged current quasi-elastic interaction candidates, also as a function of the neutrino energy. This study is also performed classifying the complete sample into two pairs of event categories: charged current quasi-elastic and non charged current quasi-elastic, and ${\nu }_{\mu }$ and ${\nu }_e$. Results show good overall agreement between data and Monte Carlo for both phases, with some small tension with a statistical significance below $2\sigma$ for some intermediate energies.

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Cited by in corpus (4)

• Solar fusion III: New data and theory for hydrogen-burning stars
• Measurement of neutron production in atmospheric neutrino interactions at Super-Kamiokande
• Benchmarks and applications of the nuclear deexcitation event generator NucDeEx
• Measurement of the Multi-Neutron ${\bar{\nu }}_{\mu }$ Charged Current Differential Cross Section at Low Available Energy on Hydrocarbon