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This page provides information about the next Double Chooz collaboration meeting dates and place, last announcements about position openings and brief hints on important dates concerning Double Chooz experiment evolution.

Improved measurements of the neutrino mixing angle theta13 with the Double Chooz detector

The collaboration releases improved measurements of theta13 with new analysis methods using the far detector data. The paper can be found at arXiv:1406.7763 . Numerical data of the ratio of the observed energy spectrum to the prediction is available here.

Indication for the disappearance of reactor electron antineutrinos in the Double Chooz experiment

On March 15th, 2012, the Double Chooz letter is accepted for publication in Physical Review Letters Citation: Y. Abe et al PRL 108, 131801, (2012) .

On December 29, 2011, the collaboration releases a first publication that can be found at arXiv:1112.6353 .

First Results from Double Chooz

On November 9, 2011, the first Double Chooz results were presented at LowNu11. The talk can be found here. Press release.

Herve de Kerret presenting first results

Rate of antineutrinos (black points, background prediction subtracted) versus days as a function of the time, from April 13th (start of the Double Chooz data taking) to September 18th. The blue line indicates the expectation in the no-oscillation scenario.

Visible prompt energy spectrum measured by the Double Chooz detector 1 km away from the 2 Chooz nuclear cores of 4.27  GW each. These data correspond to a run time of 101.5 days from April 13th to September 18th. The data, black dots, are shown as the number of neutrino events for each prompt energy bin. In blue is the expected distribution if there were no oscillations, and in red is our best fit distribution based on the data. In green, pink, and blue are the major background distributions. These backgrounds must be accounted for, and contribute to the systematic error on our best fit value.

A preliminary rate + shape analysis of the data indicated a hint for a positive value of the θ13 neutrino mixing angle at:

sin2(2θ13) = 0.085 ± 0.029(stat) ± 0.042(syst) at 68% CL

Double Chooz is now continuing to take data in order to improve its sensitivity with the far detector only. The near detector will be operational by early 2013. Thanks to its simple site configuration, comprehensive set of calibration systems and to its unique capability to measure the backgrounds in-situ during reactor off-off periods, Double Chooz is already playing a leading role in the precise determination of the θ13 mixing angle.

Combined analysis of Double Chooz and T2K for normal neutrino mass ordering. The lower panel shows the allowed regions in the plane of sin2(2θ13) and the CP phase δ for T2K alone (curves) and the Double Chooz + T2K combination (colored region). The triangle (star) corresponds to the T2K (Double Chooz + T2K) best fit point. The upper panel shows the Δχ2 marginalized over the CP-phase δ for T2K, Double Chooz alone and the combination (i.e., for each value of sin2(2θ13) the χ2 is minimized with respect to δ). Dotted horizontal lines indicate 2 and 3σ. For both neutrino mass orderings the DC+T2K combination excludes θ13 = 0 at 3σ.

Combined analysis of Double Chooz, T2K, and MINOS for normal neutrino mass ordering.

Future DC collaboration meetings

September 24-26, 2014, DC meeting at Chooz

Last meeting

March 5-7, 2014 DC Meeting at Chooz

Important dates

June 2006: Double Chooz Proposal available on arXiv

The Double Chooz proposal has been published on June 2006 and is available at

Older historical dates ...