Sterile Neutrinos and Dark Matter

Dr. Thierry Lasserre (French Alternative Energies and Atomic Commission (CEA) in Saclay, and AstroParticle and Cosmology laboratory (APC) in Paris) has been a Hans Fischer Senior Fellow since 2015. He is hosted by Prof. Stefan Schönert (Chair for Experimental Physics and Astroparticle Physics, TUM).

keV Sterile Neutrinos  & Dark Matter

Massive relic sterile neutrinos at the keV mass scale are well suited candidates to explain the Dark Matter in our Universe. Recently, X-ray telescopes might have observed an indirect evidence for the existence of relic sterile neutrinos with a mass of m = 7.1 keV/c2. But this faint signal must be tested through space physics and terrestrial experiments.

The Sterile Neutrino and Dark Matter TUM-IAS Focus Group will investigate the phenomenology and experimental perspectives for detecting Dark Matter sterile neutrinos. We plan to address the experimental prospects of searching for keV sterile neutrinos with the next generation of beta-decay and electron/neutrino capture experiments.

Providing the highest tritium source luminosity in the near future, the KATRIN experiment (KIT, Karlsruhe) could be upgraded to search for keV-scale sterile neutrinos. A sterile neutrino would manifest itself as a spectral distortion in the beta-decay energy spectrum. The measurement requires significant improvements in the modeling of the tritium beta-decay spectrum as well as substantial studies of experimental systematic uncertainties.

The Sterile Neutrino and Dark Matter TUM-IAS Focus Group will contribute to a new silicon pixel detector design, in collaboration with HLL/MPI (Munich), KIT (Karlsruhe), LBL (Berkeley), ORNL (Oak Ridge). As a first step small prototypes are be realized, as a proof of concept.

Beyond that, the Sterile Neutrino and Dark Matter TUM-IAS Focus Group will also explore other physics processes and new techniques to hunt for sterile neutrino Dark Matter.

eV Sterile Neutrinos beyond the Standard Model

In the last two decades several short baseline neutrino experiments reported results that could be interpreted as a hint for a sterile neutrino in the eV mass range. Such a new particle could mix with the active neutrino flavor, but would be insensitive to the standard weak interaction.

A search for eV-scale sterile neutrinos will be carried out with the CeSOX Experiment, which consists of an intense 144Ce antineutrino source deployed next to the large liquid scintillator detector Borexino at the Laboratory Nazionali del Gran Sasso, the world largest underground laboratory.  The smoking-gun signal of eV-sterile neutrinos is an oscillatory pattern in space and energy inside the detector volume. Data taking is schedule to start in 2016.

The Sterile Neutrino and Dark Matter TUM-IAS Focus Group will concentrate on the precision measurement of the 144Ce and 144Pr beta-spectra, the calorimetric determination of the source strength, and on the closely related physics analysis.

TUM-IAS funded doctoral candidate:
Konrad Altenmüller, Experimental Physics and Astroparticle Physics