Measurement of Reactor Antineutrino Oscillation Amplitude and Frequency at RENO

Abstract

The RENO experiment reports more precisely measured values of θ13 and |∆m 2 ee | using ∼2 200 live days of data. The amplitude and frequency of reactor electron antineutrino (νe) oscillation are measured by comparing the prompt signal spectra obtained from two identical near and far detectors. In the period between August 2011 and February 2018, the far (near) detector observed 103 212 (850 666) νe candidate events with a background fraction of 4.8% (2.0%). A clear energy and baseline dependent disappearance of reactor νe is observed in the deficit of the measured number of νe. Based on the measured far-to-near ratio of prompt spectra, we obtain sin 2 2θ13 = 0.0896 ± 0.0048(stat) ± 0.0047(syst) and |∆m 2 ee | = [2.68 ± 0.12(stat) ± 0.07(syst)] × 10 −3 eV 2 .

Observation of reactor antineutrino disappearance using delayed neutron capture on hydrogen at RENO

“…where the world average value of |∆m 2 ee | = (2.502×10 −3 eV 2 ) is used [33]. This value is consistent with the previous measurement of n-Gd result, sin 2 2θ 13 =0.0896±0.0068 within their uncertainties while the systematic uncertainty is about twice larger than that of the n-Gd result [13]. The error and its fraction of sin 2 2θ 13 by each component can be obtained using the pull terms of the χ 2 equation and are summarized in Table 6.…”

Reevaluating reactor antineutrino anomalies with updated flux predictions

“…The significant improvement in HKSS is that forbidden decays are including via nuclear shell model calculations to describe the underlying microscopic physics, allowing the authors to derive the relevant shape factors. The authors find an unspecific enhancement of the antineutrino flux at energies above 4 MeV relative to HM, mitigating somewhat the size of the infamous 5 MeV bump [30,[32][33][34] and increasing the predicted antineutrino flux.…”

“…The Spectral Anomaly: We shift our attention to the reactor ν e energy spectra measured at Bugey [36], DANSS [60], Daya Bay [61], Double Chooz [34], NEOS [32] and RENO [33]. With the exception of NEOS, each of these experiments measures the ν e spectrum at multiple positions and publishes ratios of these spectra.…”

Reactor neutrino oscillations as constraints on effective field theory

“…We identify the linear combinations of Wilson coefficients that are constrained by reactor experiments at the leading order in the SMEFT expansion. We then proceed to obtain numerical constraints on these combinations using the most recent data from the Daya Bay [21] and RENO [22] experiments.…”