Low-energy (anti)neutrino physics with Borexino: Neutrinos from the primary proton-proton fusion process in the Sun

Abstract

The Sun is fueled by a series of nuclear reactions that produce the energy that makes it shine. The primary reaction is the fusion of two protons into a deuteron, a positron and a neutrino. These neutrinos constitute the vast majority of neutrinos reaching Earth, providing us with key information about what goes on at the core of our star. Several experiments have now confirmed the observation of neutrino oscillations by detecting neutrinos from secondary nuclear processes in the Sun; this is the first direct spectral measurement of the neutrinos from the keystone proton-proton fusion. This observation is a crucial step towards the completion of the spectroscopy of pp-chain neutrinos, as well as further validation of the LMA-MSW model of neutrino oscillations

Directional detection of dark matter with two-dimensional targets

“…We expect the main irreducible background to be 14 C decay in the graphene. The landmark work on isotope enrichment used in 1991 for the Borexino experiment to assess the content of 14 C in methane in natural gas achieved levels of 1.6 × 10 −18 , relative to 12 C [53]. Accelerator mass spectroscopy during the fabrication process may be able to reduce the 14 C fraction from the 10 −18 achieved by Borexino to 10 −21 [54].…”

GooStats: A GPU-based framework for multi-variate analysis in particle physics

“…Solar neutrino produced during the proton-proton fusion in the core region of the Sun can be detected on the Earth using large liquid scintillator detectors, such as Borexino [23], KamLAND [24] and the future experiment JUNO [25], etc. The signal is the electron recoil spectrum formed by the elastic scattering between the solar neutrinos and the electrons in the target.…”