[sup 7]Be solar neutrino line: A reflection of the central temperature distribution of the Sun

Journal Article · Fri Apr 15 00:00:00 EDT 1994 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.49.3923· OSTI ID:5015708

Bahcall, J N ^[1]

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1. Institute for Advanced Study, Princeton, New Jersey 08540 (United States)

A precise test of the theory of stellar evolution can be performed by measuring the average difference in energy between the neutrino line produced by [sup 7]Be electron capture in the solar interior and the corresponding neutrino line produced in a terrestrial laboratory. This energy shift is calculated to be 1.29 keV (to an accuracy of a few percent) for the dominant ground-state to ground-state transition. The energy shift is approximately equal to the average temperature of the solar core, computed by integrating the temperature over the solar interior with a weighting factor equal to the locally produced [sup 7]Be neutrino emission. Therefore, a measurement of the energy shift is a measurement of the central temperature distribution of the Sun. The energy profile of the [sup 7]Be line is derived analytically and is evaluated numerically. The line shape is asymmetric: on the low-energy side, the line shape is Gaussian with a half-width at half-maximum of 0.6 keV and, on the high-energy side, the line shape is exponential with a half-width at half-maximum of 1.1 keV. The effective temperature of the high-energy exponential tail is 15[times]10[sup 6] K. The energy profile of the [sup 7]Be neutrino line should be taken into account in calculations of vacuum neutrino oscillations and of the absorption cross section for [sup 7]Be solar neutrinos incident on [sup 7]Li nuclei. The characteristic modulation of the [sup 7]Be line shape that would be caused by either vacuum neutrino oscillations or by matter-enhanced (MSW) neutrino oscillations is shown to be small. Other frequently discussed weak interaction solutions to the solar neutrino problem are also not expected to change significantly the line profile.

• OSTI ID: 5015708
• Journal Information: Physical Review, D (Particles Fields); (United States), Vol. 49:8; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
Pa
BERYLLIUM 7
SOLAR NEUTRINOS
SPECTRAL SHIFT
SUN
TEMPERATURE DISTRIBUTION
CROSS SECTIONS
ELECTRON CAPTURE
GROUND STATES
NEUTRINO OSCILLATION
ALKALINE EARTH ISOTOPES
BERYLLIUM ISOTOPES
BETA DECAY RADIOISOTOPES
CAPTURE
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ENERGY LEVELS
EVEN-ODD NUCLEI
FERMIONS
ISOTOPES
LEPTONS
LIGHT NUCLEI
MAIN SEQUENCE STARS
MASSLESS PARTICLES
NEUTRINOS
NUCLEI
RADIATIONS
RADIOISOTOPES
SOLAR PARTICLES
SOLAR RADIATION
STARS
STELLAR RADIATION
662210* - Specific Theories & Interaction Models
Particle Systematics- Unified Theories & Models- (1992-)
662430 - Properties of Leptons- (1992-)