KamLAND, solar antineutrinos and their magnetic moment

Abstract

We investigate the possibility of detecting solar antineutrinos with the KamLAND experiment. These antineutrinos are predicted by spin-flavor oscillations at a significant rate even if this mechanism is not the leading solution to the SNP. The recent evidence from SNO shows that a) the neutrino oscillates, only around 34% of the initial solar neutrinos arrive at the Earth as electron neutrinos and b) the conversion is mainly into active neutrinos, however a non e, mu, tau component is allowed: the fraction of oscillation into non-mu-tau neutrinos is found to be cos^2(alpha) = 0.08^{+0.20}_{-0.40}. This residual flux could include sterile neutrinos and/or the antineutrinos of the active flavors. KamLAND is potentially sensitive to antineutrinos derived from solar ^8 B neutrinos. In case of negative results, we find that KamLAND could put strict limits on the flux of solar antineutrinos, Phi(^8 B) < 1.0 times 10^4 cm^{-2} s^{-1}, more than one order of magnitude smaller than existing limits, and on their appearance probability P < 0.20-0.15% (95% CL) after 1-3 years of operation. Assuming a concrete model for antineutrino production by spin-flavor precession, this upper bound implies an upper limit on the product of the intrinsic neutrino magnetic moment and the value of the solar magnetic field mu B < 10^{-21} MeV (95% CL). For B ~ 10-100 kG, we would have mu < 10^{-11}-10^{-12} mu_B (95% CL). In the opposite case, if spin-flavor precession is indeed at work even at a non-leading rate, the additional flux of antineutrinos could strongly distort the signal spectrum seen at KamLAND at energies above 4-5 MeV and their contribution should properly be taken into account.

References in corpus (5)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• The SNO Solar Neutrino Data, Neutrinoless Double Beta-Decay and Neutrino Mass Spectrum
• KamLAND potentiality on the determination of Neutrino mixing parameters in the post SNO-NC era
• The solar neutrino puzzle: present situation and future scenarios
• Solving the solar neutrino problem with kamLAND and BOREXINO

Cited by in corpus (9)

• Cosmological Parameters from the 2003 flight of BOOMERANG
• Solar Neutrinos Before and After KamLAND
• Combining first KamLAND results with solar neutrino data
• Constraining the neutrino magnetic moment with anti-neutrinos from the Sun
• Neutrino mass parameters from Kamland, SNO and other solar evidence
• LMA and sterile neutrinos: a case for resonance spin flavour precession?
• KamLAND, solar antineutrinos and the solar magnetic field
• KamLAND Bounds on Solar Antineutrinos and neutrino transition magnetic moments
• Neutrino transition magnetic moments and the solar magnetic field on the light of the Kamland evidence