The reactor neutrino anomaly: status and recent developments

The observed antineutrino flux from nuclear reactors is consistently lower thanpredicted. This anomaly could hint at oscillations of active neutrinos into anew sterile neutrino species, or it could simply be a reflection ofunderestimated systematic uncertainties in the theoretical flux prediction. Wereview the status of both hypotheses in view of recent developments. Inparticular, we scrutinize recent Daya Bay results, which aim to determinewhether the deficit depends on the isotope from which neutrinos are produced (aswould be likely if the problem is with the flux prediction), or is independentthereof (as would be expected if the sterile neutrino hypothesis is true). Wealso comment on new short-baseline data, and we discuss reactor data in thecontext of a global fit.