We performed inelastic neutron scattering measurements on single crystals of NdFe$_{3}$($^{11}$BO$_{3}$)$_{4}$ to explore the magnetic excitations, to establish the underlying Hamiltonian, and to reveal the detailed nature of hybridization between th
e 4$f$ and 3$d$ magnetism. The observed spectra exhibiting a couple of key features, i.e., anti-crossing of Nd- and Fe-excitations and anisotropy gap at the antiferromagnetic zone center, are explained by the magnetic model including spin interaction in the framework of weakly-coupled Fe$^{3+}$ chains, interaction between the Fe$^{3+}$ and Nd$^{3+}$ moments, and single-ion anisotropy derived from Nd$^{3+}$ crystal field. The combination of the measurements and calculations reveals that the hybridization between 4$f$ and 3$d$ magnetism propagates the local magnetic anisotropy of the Nd$^{3+}$ ion to the Fe$^{3+}$ network, resulting in the bulk structure of multiferroics.
The reactor neutrino and gallium anomalies can be tested with a 3-4 PBq (75-100 kCi scale) 144Ce-144Pr antineutrino beta-source deployed at the center or next to a large low-background liquid scintillator detector. The antineutrino generator will be
produced by the Russian reprocessing plant PA Mayak as early as 2014, transported to Japan, and deployed in the Kamioka Liquid Scintillator Anti-Neutrino Detector (KamLAND) as early as 2015. KamLANDs 13 m diameter target volume provides a suitable environment to measure the energy and position dependence of the detected neutrino flux. A characteristic oscillation pattern would be visible for a baseline of about 10 m or less, providing a very clean signal of neutrino disappearance into a yet-unknown, sterile neutrino state. This will provide a comprehensive test of the electron dissaperance neutrino anomalies and could lead to the discovery of a 4th neutrino state for Delta_m^2 > 0.1 eV^2 and sin^2(2theta) > 0.05.
We propose to test for short baseline neutrino oscillations, implied by the recent reevaluation of the reactor antineutrino flux and by anomalous results from the gallium solar neutrino detectors. The test will consist of producing a 75 kCi 144Ce - 1
44Pr antineutrino source to be deployed in the Kamioka Liquid Scintillator Anti-Neutrino Detector (KamLAND). KamLANDs 13m diameter target volume provides a suitable environment to measure energy and position dependence of the detected neutrino flux. A characteristic oscillation pattern would be visible for a baseline of about 10 m or less, providing a very clean signal of neutrino disappearance into a yet-unknown, sterile state. Such a measurement will be free of any reactor-related uncertainties. After 1.5 years of data taking the Reactor Antineutrino Anomaly parameter space will be tested at > 95% C.L.
