On the origin of the reactor antineutrino anomalies

by Alain Letourneau (CEA/Saclay)

Thursday 13 Jul 2023, 10:00 → 12:00 Europe/Berlin

Nußallee 12/1.049 (PI) - Conference Room II (PI)

Reactor antineutrino anomalies are decade-long puzzles in neutrino physics. They are deviations of the order of a few per cent, both in norm and shape, between measurements and the Huber-Mueller prediction. They have been observed in all recent high-precision experiments conducted near nuclear reactors. They may arise from the existence of light sterile neutrinos, but recent experiments on very short baselines have rejected this hypothesis.
In that seminar, after reviewing the phenomenological approach that led to the discovery of the anomalies, I will present the state of the art of experimental and theoretical results to delimit their origin. Then I will focus on the recent improvements we have made to the modelling of beta decay. These improvements reproduce the measured antineutrino spectra and show disagreements with the reference beta spectra used to construct the Huber-Mueller prediction. This lead us to the conclusion that experimental biases in the reference beta spectra could be at the origin of the anomalies.

Seminaire_Bonn_03072022_bis.pdf