Two Gallium data sets, spin flavour precession and KamLAND

Abstract

We reexamine the possibility of a time modulation of the low energy solar neutrino flux which is suggested by the average decrease of the Ga data in line with our previous arguments. We perform two separate fits to the solar neutrino data, one corresponding to 'high' and the other to 'low' Ga data, associated with low and high solar activity respectively. We therefore consider an alternative to the conventional solar+KamLAND fitting, which allows one to explore the much wider range of the ${\theta }_{12}$ angle permitted by the KamLAND fitting alone. We find a solution with parameters $\Delta m_{21}^2=8.2\times 10^{-5}e{V}^2,ta{n}^2\theta =0.31$ in which the 'high' and the 'low' Ga rates lie far apart and are close to their central values and is of comparable quality to the global best fit, where these rates lie much closer to each other. This is an indication that the best fit in which all solar and KamLAND data are used is not a good measure of the separation of the two Ga data sets, as the information from the low energy neutrino modulation is dissimulated in the wealth of data. Furthermore for the parameter set proposed one obtains an equally good fit to the KamLAND energy spectrum and an even better fit than the 'conventional' LMA one for the reactor antineutrino survival probability as measured by KamLAND.

V2: 15 pages, 3 eps figures, fit improved, final version to appear in Journal of Physics G

References in corpus (20)

• First Results from KamLAND: Evidence for Reactor Anti-Neutrino Disappearance
• Measurement of Neutrino Oscillation with KamLAND: Evidence of Spectral Distortion
• Determination of Solar Neutrino Oscillation Parameters using 1496 Days of Super-Kamiokande-I Data
• New solar opacities, abundances, helioseismology, and neutrino fluxes
• Electron Energy Spectra, Fluxes, and Day-Night Asymmetries of ${}^8$B Solar Neutrinos from the 391-Day Salt Phase SNO Data Set
• The angular distribution of the reaction ${\bar{\nu }}_e+p\to e^{+}+n$
• Measurement of the Solar Neutrino Capture Rate by the Russian-American Gallium Solar Neutrino Experiment During One Half of the 22-Year Cycle of Solar Activity
• Measurements of extremely low radioactivity levels in BOREXINO
• Solar Neutrinos Before and After Neutrino 2004
• Update of the solar neutrino oscillation analysis with the 766 Ty KamLAND spectrum
• A Search for Periodicities in the ${}^8$B Solar Neutrino Flux Measured by the Sudbury Neutrino Observatory
• A search for periodic modulations of the solar neutrino flux in Super-Kamiokande-I
• Resonance spin flavour precession and solar neutrinos
• Power-Spectrum Analyses of Super-Kamiokande Solar Neutrino Data: Variability and its Implications for Solar Physics and Neutrino Physics
• Histogram Analysis of Gallex, GNO and Sage Neutrino Data: Further Evidence for Variability of the Solar Neutrino Flux
• Analysis of Super-Kamiokande 5-day Measurements of the Solar Neutrino Flux
• KamLAND neutrino spectra in energy and time: Indications for reactor power variations and constraints on the georeactor
• LMA and sterile neutrinos: a case for resonance spin flavour precession?
• Low Energy Solar Neutrinos and Spin Flavour Precession
• ${}^{7}Be$ Neutrino Signal Variation in KamLAND

Cited by in corpus (3)

• Combined analysis of solar neutrino and solar irradiance data: further evidence for variability of the solar neutrino flux and its implications concerning the solar core
• Light sterile neutrinos, spin flavour precession and the solar neutrino experiments
• SNO+: predictions from standard solar models and spin flavour precession