Tritium and rhenium as a probe of cosmic neutrino background

Amand Faessler (1) , Rastislav Hodák (2) , Sergey Kovalenko (3) , Fedor Šimkovic (2, 4)

1 Insitut für Theoretische Physik [Tübingen]
2 Department of Nuclear Physics and Biophysics
3 Departamento de Física
4 BLTP - Bogoliubov Laboratory of Theoretical Physics [Dubna]

We analyze the possibility of detection of cosmological relic neutrinos via neutrino capture on beta decaying nuclei. This reaction has no threshold in neutrino energy, which is crucial for searching for relic neutrinos possessing very low energies. We focus on tritium (3 H) and rhenium (187 Re) beta radioactive isotopes to be used in the Karlsruhe tritium neutrino mass (KATRIN) experiment and project, called the " Microcalorimeter Arrays for a Rhenium Experiment " (MARE), dedicated to measurement of the electron neutrino mass at sub-eV scale. We examine these experiments from the viewpoint of searching for the cosmological neutrinos via neutrino capture. We conclude that even with possible gravitational clustering of relic neutrinos the prospects for their detection in these and other similar experiments are not optimistic. Nevertheless KATRIN and MARE experiments could establish some useful constraints on density of relic neutrinos.

Mots clés: relic neutrinos; neutrino capture; beta decay

Amand Faessler, Rastislav Hodák, Sergey Kovalenko, Fedor Šimkovic. Tritium and rhenium as a probe of cosmic neutrino background. Journal of Physics G: Nuclear and Particle Physics, 2011, 38 (7), pp.75202. ⟨10.1088/0954-3899/38/7/075202⟩. ⟨hal-00628288⟩