The Double Chooz experiment uses antineutrinos emitted from the Chooz nuclear power plant (France) to measure the oscillation mixing parameter θ13. By using two detectors at different baselines, a precise measurement of antineutrinos disappearance is anticipated. The Far detector has been taking physics data since April 2011, while the Near detector is under construction. Data from April 13th 2011 to March 30th 2012 taken with the Far detector only have been analyzed and an indication for antineutrino disappearance, consistent with the current neutrino oscillation hypothesis, has been found. The best fit value for the neutrino mixing parameter sin2(2θ13) is 0.109 ± 0.030(stat.) ± 0.025(syst.). This thesis present an accurate description of the Double Chooz experiment, with particular emphasis on the Far detector and its acquisition system. The main focus of the thesis is the accurate study of the correlated background affecting the Double Chooz antineutrinos sample and its impact on the measurement of the mixing parameter θ13. A general overview of the current experimental scenario which aim to the characterization of the neutrino oscillation is also provided, focusing on the recent results obtained in this field.
Correlated background and impact on the measurement of theta_13 with the Double Chooz detector