Recoilless resonant capture of monoenergetic electron antineutrinos (Moessbauer antineutrinos) emitted in bound-state beta-decay in the system 3H - 3He is discussed. The recoilfree fraction including a possible phonon excitation due to local lattice expansion and contraction at the time of the nuclear transition, homogeneous and inhomogeneous line broadening, and the relativistic second-order Doppler effect are considered. It is demonstrated that homogeneous line broadening is essential due to stochastic magnetic relaxation processes in a metallic lattice. Inhomogeneous line broadening plays an equally important role. An essential issue which has been overlooked up to now, is an energy shift of the resonance line due to the direct influence of the binding energies of the 3H and 3He atoms in the lattice on the energy of the electron antineutrinos. This energy shift as well as the second-order Doppler shift exhibit variations in a non-perfect (inhomogeneous) lattice and may seriously jeopardize the observation of Moessbauer antineutrinos. If successful in spite of these enormous difficulties, Moessbauer antineutrino experiments could be used to gain new and deep insights into the nature of neutrino oscillations, determine the neutrino mass hierarchy as well as up to now unknown oscillation parameters, search for sterile neutrinos, and measure the gravitational redshift of electron antineutrinos in the field of the Earth.
Resonant Spin-Flavor Precession Solution to the Solar Neutrino Problem and electron antineutrinos from the Sun
我们找到了太阳中微子问题的共振旋味旋进解的质量差平方、磁场和混合角的允许区域,并与所有作用太阳中微子实验的数据进行了拟合。对于固定的中微子跃迁磁矩,在很宽的范围内,对于某些离散的磁场区域,允许存在依赖于混合角的典型质量差区域。除了具有最低场强的第一个允许范围之外,其他离散允许区域内的磁场幅度基本上取决于太阳对流区中规则磁场轮廓的形状。对于非零中微子混合,可以在99.9% C. L.混合的上限,起源于SuperKamiokande探测器中未观察到电子反中微子。该极限也对磁场分布敏感。当在67% C. L.由于镓实验与其它实验的不一致性,存在另一个更严格的上限。一个新的允许区域出现在一个额外的假设的情况下,Homestake数据是1.3倍小于实验的事件率。
$^{163}$Ho has been considered as a suitable candidate for the capture of relic antineutrinos. However, the detection of the relic antineutrino using $^{163}$Ho is extremely challenging with current techniques. Therefore, we have searched for new targets for relic antineutrino detections through the resonant capture on nuclides undergoing electron capture. We have investigated nuclear and atomic properties of all nuclides. And we finally propose $^{131}$Ba, $^{159}$Dy, $^{175}$Hf, $^{195}$Au, and $^{243}$Cm as new candidates for the relic antineutrino detection, and call for high precise exper…
In $ν/\barν$-N/A interactions SIS is technically defined in terms of the four-momentum transfer to the hadronic system as non-resonant meson production with $Q^2 \lessapprox 1~GeV^2$. This non-resonant meson production intermixes with resonant meson production in a regime of similar effective hadronic mass W of the interaction. As $Q^2$ grows and surpasses this $\approx 1~GeV^2$ limit, non-resonant interactions begin to take place with quarks within the nucleon indicating the start of DIS region. SIS and DIS regions have received varying degrees of attention from the community. While the theor…