Solar neutrino spectroscopy

Abstract

More than forty years after the first detection of neutrinos from the Sun, the spectroscopy of solar neutrinos has proven to be an on-going success story. The long-standing puzzle about the observed solar neutrino deficit has been resolved by the discovery of neutrino flavor oscillations. Today's experiments have been able to solidify the standard MSW-LMA oscillation scenario by performing precise measurements over the whole energy range of the solar neutrino spectrum.This article reviews the enabling experimental technologies: On the one hand mutlikiloton-scale water Cherenkov detectors performing measurements in the high-energy regime of the spectrum, on the other end ultrapure liquid-scintillator detectors that allow for a lowthreshold analysis. The current experimental results on the fluxes, spectra and time variation of the different components of the solar neutrino spectrum will be presented, setting them in the context of both neutrino oscillation physics and the hydrogen fusion processes embedded in the Standard Solar Model.Finally, the physics potential of state-of-the-art detectors and a next-generation of experiments based on novel techniques will be assessed in the context of the most interesting open questions in solar neutrino physics: a precise measurement of the vacuum-matter transition curve of electron-neutrino oscillation probability that offers a definitive test of the basic MSW-LMA scenario or the appearance of new physics; and a first detection of neutrinos from the CNO cycle that will provide new information on solar metallicity and stellar physics.

Neutrino–nuclear responses for astro-neutrinos, single beta decays and double beta decays

“…Astro-neutrinos such as solar neutrinos and supernova neutrinos are interesting in view of both neutrino physics and astrophysics. The observations of solar neutrinos provide evidences for the neutrino matter oscillations as well as nuclear fusion reactions in the sun, and those of the supernova neutrinos probe the explosion process, as described extensively in the review articles [6,7,8,9,10]. So, these observations have opened the new field of neutrino astronomy.…”

“…Historical reviews and extensive previous works on the neutrino-nuclear responses are given in [1,2,3,4,5] and references therein, those on astro-neutrinos in, e.g. [6,7,8,9,10,11,12,13,14] and references therein, and reviews on DBDs are given in, e.g. [15,16,17,18,19,20,21,22,23,24] and references therein.…”

The Explosion Mechanism of Core-Collapse Supernovae: Progress in Supernova Theory and Experiments

“…Direct constraints on the first second of the explosion are expected from the future detection of neutrinos (e.g. Wurm et al 2012, Müller et al 2014a) and gravitational waves (Ott 2009, Kotake 2013, Müller et al 2013) from a Galactic supernova. The future detection of the diffuse neutrino background will globally constrain both the physics of the explosion and the supernova rate (Beacom 2010).…”

Electromagnetic neutrinos in laboratory experiments and astrophysics

“…The precision measurements of low‐energy neutrinos from the Sun in the ongoing and forthcoming solar neutrino experiments will not only provide us with more accurate values of neutrino oscillation parameters , but also offer a precious opportunity to test the Mikheyev‐Smirnov‐Wolfenstein (MSW) matter effect and to probe the solar properties, such as the core metallicity (by measuring the CNO neutrino flux) and the total luminosity (through determining the neutrino flux). Furthermore, the observations of solar neutrinos in the future water‐Cherenkov detector Hyper‐Kamiokande and liquid‐scintillator detectors SNO+ , JUNO , RENO50 and LENA will greatly improve current knowledge about the electromagnetic properties of neutrinos.…”

“…There will be a liquid‐scintillator detector with a 20 kiloton target mass and a high energy resolution of at JUNO, and the LENA detector will be 2.5 times larger. In consequence, JUNO (LENA ) will register about four thousand (ten thousand) 7 Be elastic ‐ events per day in its detectable window above 250 keV, which means that the statistical uncertainties can be negligible after years of data taking. Therefore, the achievable limit on the neutrino magnetic dipole moment mainly depends on the systematics, and in particular on the radioactive and cosmogenic backgrounds.…”