Solar-cycle modulation of event rates in the chlorine solar neutrino experiment

Journal Article · Mon Apr 01 04:00:00 UTC 1991 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169856· OSTI ID:5732499

Bahcall, J N; Press, W H ^[1]

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1. Institute for Advanced Study, Princeton, NJ (USA) Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (USA)

The time dependence of the event rates in the Homestake chlorine solar neutrino experiment are reexamined using new Ar-37 production data covering the period from late 1986 to mid-1989. The data span almost two complete solar cycles. A careful statistical analysis using nonparametric rank-order statistics is used to calculate quantitative significance levels that do not depend on experimental errors. The results show that the Ar-37 production rate in the experiment is anticorrelated with solar activity for approximately 1977-1989. The shape of the Ar-37 production rate is different from the inverted sunspot activity curve. The Ar-37 production rate is better descrbed by a skewed sawtooth function than by the sunspot number. The best-fitting sawtooth function with sunspot period has a slow rise and a rapid decline. The Ar-37 maximum occurs about 12.5 yr after the solar sunspot minimum, while minimum Ar-37 production is more nearly simultaneous with the sunspot maximum. 42 refs.

• OSTI ID: 5732499
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 370; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANNUAL VARIATIONS
ARGON
ARGON 37
ARGON ISOTOPES
BETA DECAY RADIOISOTOPES
DAYS LIVING RADIOISOTOPES
DETECTION
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ELEMENTS
EVEN-ODD NUCLEI
FERMIONS
FLUIDS
GASES
ISOTOPES
LEPTONS
LIGHT NUCLEI
MASSLESS PARTICLES
MATHEMATICS
NEUTRINO DETECTION
NEUTRINOS
NONMETALS
NUCLEI
NUCLEOSYNTHESIS
RADIATION DETECTION
RADIATIONS
RADIOISOTOPES
RARE GASES
SOLAR ACTIVITY
SOLAR CYCLE
SOLAR NEUTRINOS
SOLAR PARTICLES
SOLAR RADIATION
STARSPOTS
STATISTICS
STELLAR ACTIVITY
STELLAR RADIATION
SUNSPOTS
SYNTHESIS
TIME DEPENDENCE
VARIATIONS