Double Chooz: Optimizing CHOOZ for a possible θ13 measurement

S.A. Dazeley

doi:10.1016/j.nuclphysbps.2006.02.056

Reactor rate modulation oscillation analysis with two detectors in Double Chooz

Journal of High Energy Physics ◽

10.1007/jhep01(2021)190 ◽

2021 ◽

Vol 2021 (1) ◽

Author(s):

T. Abrahão ◽

◽

H. Almazan ◽

J. C. dos Anjos ◽

S. Appel ◽

...

Keyword(s):

Reactor Power ◽

Background Model ◽

Fast Neutrons ◽

Mixing Angle ◽

Oscillation Analysis ◽

Central Value ◽

Double Chooz ◽

Model Independent ◽

Best Fit

Abstract A θ13 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 θ13 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 $$ {\overline{\nu}}_e $$ ν ¯ e 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 9Li decays. The background-model-independent determination of the mixing angle yields sin2(2θ13) = 0.094 ± 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 θ13 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.

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Non-standard interactions in SMEFT confronted with terrestrial neutrino experiments

Journal of High Energy Physics ◽

10.1007/jhep03(2021)019 ◽

2021 ◽

Vol 2021 (3) ◽

Author(s):

Yong Du ◽

Hao-Lin Li ◽

Jian Tang ◽

Sampsa Vihonen ◽

Jiang-Hao Yu

Keyword(s):

Neutrino Oscillation ◽

New Physics ◽

Effective Field ◽

Scalar Leptoquark ◽

Double Chooz ◽

The Standard Model ◽

Reactor Neutrino ◽

Model Independent ◽

Neutrino Experiments ◽

Individual Dimension

Abstract The Standard Model Effective Field Theory (SMEFT) provides a systematic and model-independent framework to study neutrino non-standard interactions (NSIs). We study the constraining power of the on-going neutrino oscillation experiments T2K, NOνA, Daya Bay, Double Chooz and RENO in the SMEFT framework. A full consideration of matching is provided between different effective field theories and the renormalization group running at different scales, filling the gap between the low-energy neutrino oscillation experiments and SMEFT at the UV scale. We first illustrate our method with a top- down approach in a simplified scalar leptoquark model, showing more stringent constraints from the neutrino oscillation experiments compared to collider studies. We then provide a bottom-up study on individual dimension-6 SMEFT operators and find NSIs in neutrino experiments already sensitive to new physics at ∼20 TeV when the Wilson coefficients are fixed at unity. We also investigate the correlation among multiple operators at the UV scale and find it could change the constraints on SMEFT operators by several orders of magnitude compared with when only one operator is considered. Furthermore, we find that accelerator and reactor neutrino experiments are sensitive to different SMEFT operators, which highlights the complementarity of the two experiment types.

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