Particle Physics Seminar

I will present the results of the search for the electron antineutrinos from the Sun
with Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND). There is no known
direct production of the electron antineutrinos in the Sun. However, in the some theoretical
models with the large neutrino magnetic moment antineutrinos from the Sun can be produced e.g.
via Spin Flavor Precession mechanism (SFP). Search for solar antineutrinos potentially can
provide new information about fundamental properties of neutrinos. The most sensitive
one-kiloton antineutrino detector KamLAND gives the possibility to search for such antineutrinos.
The analysis described in this presentation is based on 1425.9 days of data collection in KamLAND.
The search for the electron antineutrinos have been made within 8.8-16.3MeV antineutrino energy
range, that is above energies of reactor antineutrinos and where properties of the solar B8
neutrinos are well studied. Based on the number of observed candidates and estimated background
rates the upper limit on the electron antineutrino flux and probability of conversion electron
neutrinos produced in the Sun was determined. Using the conversion probability the upper limit
on the product of the neutrino magnetic moment and the transverse component of the magnetic field
in the core of the Sun can be set. Observed limit on electron antineutrino flux can be used on
the diffuse Supernovae neutrino flux. The estimated background rates can make significant impact
on the design of the future neutrino scintillator detectors.