arXiv subjects

A. Fukumi

Publications and source records attributed to A. Fukumi.

3 recordsLinked to original sources

arXiv2009

Parity violating observables in radiative neutrino pair emission from metastable atoms

We report on a possibility of measuring parity violating effects in radiative neutrino pair emission from metastable atoms; asymmetric angular distribution of emitted photons from oriented atoms and emergent circular polarization. Their observation, along with the continuous photon energy spectrum which has 6 thresholds, may be interpreted as events being a combined weak and QED process, emission of $γν_i ν_j$ in the final state. The method may greatly help to perform neutrino mass spectroscopy using atoms, a systematic determination of the neutrino mass matrix.

hep-ph↗

arXiv2009

Toward CP-even Neutrino Beam

The best method of measuring CP violating effect in neutrino oscillation experiments is to construct and use a neutrino beam made of an ideal mixture of $\barν_e$ and $ν_e$ of monochromatic lines. The conceptual design of such a beam is described, together with how to measure the CP-odd quantity. We propose to exploit an accelerated unstable hydrogen-like heavy ion in a storage ring, whose decay has both electron capture and bound beta decay with a comparable fraction.

hep-ex↗

arXiv2008

Macro-coherent two photon and radiative neutrino pair emission

We discuss a possibility of detecting a coherent photon pair emission and related radiative neutrino pair emission from excited atoms. It is shown that atoms of lambda- and ladder-type three level system placed in a pencil-like cylinder give a back to back emission of two photons of equal energy $Δ/2$, sharply peaked with a width $\propto $ 1/(target size) and well collimated along the cylinder axis. This process has a measurable rate $\propto$ (target number density) $^2 \times$ target volume, while a broader spectral feature of one-photon distribution separated by (mass sum of a neutrino pair)$^2/(2Δ)$ from the two photon peak may arise from radiative neutrino pair emission, with a much smaller rate.

hep-ph↗