Direct search for keV-sterile neutrino in nuclear decay. Troitsk nu-mass
A. A. Nozik+*, V. S. Pantuev+
+Institute for Nuclear Research Russian Academy of Sciences, 117312 Moscow, Russia
*Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
Abstract
We present a brief review of experimental status in searching
for
hypothetical sterile neutrino in nuclear decay in laboratory testing. The
main idea is based on search for an additional small component in the
β-spectrum or a shift in the internal electron conversion energy.
For example, in a three-body β-decay it looks like a kink in the
continuous spectrum shifted by the value of sterile neutrino mass from
the spectrum endpoint.
After a short general motivation for such a search we discuss the
way how to find sterile neutrino in the nuclear β-decay and present
the current status of upper limits on sterile neutrino mixing with
electron antineutrino. The advantages and problems arising in the precise
measurements of β-spectrum are demonstrated on the basis of the
"Troitsk nu-mass" experiment by presenting the all measurement and
analysis procedures in details. At the end we discuss the nearest future
of such experiments.