Search for Large Extra Dimensions in the DANSS Experiment

Abstract

The DANSS detector is located near the power reactor at the Kalinin Nuclear Power Plant (at distances of 10.9–12.9 m) and is able to detect up to 5000 antineutrino events per day. The results of the search for Large Extra Dimensions in the simplest case of a single dominant large extra dimension are discussed. The particle oscillations to a finite-size extra dimension are assumed in this theory, and its predictions depend on the difference between the squared masses, as well as on the absolute scale of the neutrino masses. The sensitivity of the experiment to Large Extra Dimensions for various values of the model parameters such as the size of the large extra dimension a and the lightest-neutrino mass \({{m}_{0}}\) can be determined by its Monte Carlo simulation. No statistically significant indications of the existence of Large Extra Dimensions have been obtained from the analysis of almost 5.8 million antineutrino events (the statistical confidence of the best point is only 2.0σ (1.8σ) for the normal (inverted) ordering of neutrino masses). The bounds have been determined for the size of the extra dimension and the lightest neutrino mass. These bounds for a number of regions are the best in the world. These bounds exclude a large fraction of the parameters preferable for explaining the gallium anomaly and the reactor antineutrino anomaly in this model, including the corresponding best points.