The Double Chooz Neutrino Experiment: First Multi-Detector Result
At 51st Rencontres de Moriond conference (La Thuile, Italy), the Double Chooz collaboration has presented its first θ13 measurement exploiting the combination of 2 years of single-detector data (since 2011) and 9 months of double-detector data (since January 2015). The measured value for sin2(2θ13) is (0.111±0.018), which is ~30% larger (~1.4σ significance) than the most precise Daya Bay measurement (0.084±0.005). This new result is in better agreement with T2K and NOvA beam measurements. The reactor results in combination with beam experiments are key elements for the first positive observation of neutrino CP-violation.
The reported precision is expected to rapidly improve with statistics. However, it demonstrates the capability of the experimental setup, benefiting from its simple 2 reactor configuration leading a negligible reactors systematics (<1‰), excellent quality double detectors as well as a remarkable analysis strategy allowing for major active background rejection and accurate control of the energy scale exploiting the latest FADC electronic readout technology. With only 9months of double-detector data, Double Chooz has achieved the expected best sensitivity as quoted in the original proposal (2006). This demonstrates that the experiment’s precision is well beyond original expectations, holding additional complementarity to other measurements. The combined reactor neutrino θ13 measurement (Daya Bay, Double Chooz and RENO) is expected to be the most precise in the world for decades with expected impact to most of the future neutrino oscillation measurements.
The Double Chooz experiment is led by an international collaboration of about 100 scientists from 7 countries: Brazil, France, Germany, Japan, Russia, Spain and USA.
Double Chooz Contact: Hervé de Kerret [firstname.lastname@example.org] (CNRS/IN2P3 - APC Laboratory, Paris, France)