Reactor Rate Modulation oscillation analysis with two detectors in Double Chooz

Abstract

A ${\theta }_{13}$ oscillation analysis based on the observed antineutrino rates at the Double Chooz far and near detectors for different reactor power conditions is presented. This approach provides a so far unique simultaneous determination of ${\theta }_{13}$ and the total background rates without relying on any assumptions on the specific background contributions. The analysis comprises 865 days of data collected in both detectors with at least one reactor in operation. The oscillation results are enhanced by the use of 24.06 days (12.74 days) of reactor-off data in the far (near) detector. The analysis considers the \nue interactions up to a visible energy of 8.5 MeV, using the events at higher energies to build a cosmogenic background model considering fast-neutrons interactions and ${}^9$Li decays. The background-model-independent determination of the mixing angle yields sin${}^2(2{\theta }_{13})=0.094\pm 0.017$, being the best-fit total background rates fully consistent with the cosmogenic background model. A second oscillation analysis is also performed constraining the total background rates to the cosmogenic background estimates. While the central value is not significantly modified due to the consistency between the reactor-off data and the background estimates, the addition of the background model reduces the uncertainty on ${\theta }_{13}$ to 0.015. Along with the oscillation results, the normalization of the anti-neutrino rate is measured with a precision of 0.86\%, reducing the 1.43\% uncertainty associated to the expectation.

References in corpus (19)

• Direct Evidence for Neutrino Flavor Transformation from Neutral-Current Interactions in the Sudbury Neutrino Observatory
• First Results from KamLAND: Evidence for Reactor Anti-Neutrino Disappearance
• Improved Predictions of Reactor Antineutrino Spectra
• On the determination of anti-neutrino spectra from nuclear reactors
• Evidence for an oscillatory signature in atmospheric neutrino oscillation
• Evidence for muon neutrino oscillation in an accelerator-based experiment
• Constraint on the Matter-Antimatter Symmetry-Violating Phase in Neutrino Oscillations
• Measurement of electron antineutrino oscillation with 1958 days of operation at Daya Bay
• First Double Chooz ${\theta }_{13}$ Measurement via Total Neutron Capture Detection
• Experimental Determination of the Antineutrino Spectrum of the Fission Products of ${}^{238}$U
• First Measurement of θ_13 from Delayed Neutron Capture on Hydrogen in the Double Chooz Experiment
• Spectral Measurement of the Electron Antineutrino Oscillation Amplitude and Frequency using 500 Live Days of RENO Data
• Measurement of ${\theta }_{13}$ in Double Chooz using neutron captures on hydrogen with novel background rejection techniques
• Background-independent measurement of ${\theta }_{13}$ in Double Chooz
• What is $\Delta m_{ee}^2$ ?
• Direct Measurement of Backgrounds using Reactor-Off Data in Double Chooz
• Yields and production rates of cosmogenic ${}^9$Li and ${}^8$He measured with the Double Chooz near and far detectors
• Characterization of the Spontaneous Light Emission of the PMTs used in the Double Chooz Experiment
• The antineutrino energy structure in reactor experiments

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• Cerium ruthenium low-energy antineutrino measurements for safeguarding military naval reactors