Statistical Data Analysis in the DANSS Experiment Including Antineutrino Relative Count Rate Data as a Function of Distance

The DANSS detector, i.e., a scintillation detector with a sensitive volume of 1 m(3), is installed at the Kalinin Nuclear Power Plant under the reactor on a moving stage. The distance from the detector center to the reactor core center can be varied from 10.9 to 12.9 m. The detector records about 5000 events of inverse beta decay per day with a background level from cosmic muons of the order of two percent. An analysis on the search for the sterile neutrino, based on only the ratio of spectra shapes at various distances is compared with an analysis which, along with the shape, accounts for changes in relative count rates. The effect of systematic errors contributing to the analysis using relative count rates is discussed. The analysis considering three detector positions is described.