Improved modeling of reactor antineutrino spectra

Abstract

Over the last decades, Inverse Beta Decay antineutrino experiments conducted at short and long baselines from nuclear reactors have revealed significant discrepancies on both the rate and shape of the measured spectra compared to state-of-the-art predictions. No evidence for an experimental bias has been demonstrated, and the sterile neutrino interpretation of the reactor antineutrino anomaly is currently disfavored by recent very short baseline reactor experiments. The validity of the predictions is then questioned as the source of the observed discrepancies. This motivates a revision of the reactor antineutrino spectrum modeling, which will also be useful for a new generation of reactor experiments investigating Coherent Elastic Neutrino-Nucleus Scattering. In this context, a revisited prediction of reactor antineutrino spectra using the summation method is currently underway, including the construction of a comprehensive uncertainty budget associated to both modeling and nuclear data. The ingredients of this new prediction along with preliminary results are presented in this proceeding.