Constraining sterile neutrinos using reactor neutrino experiments

Models of neutrino mixing involving one or more sterile neutrinos have resurrected their importance in the light of recent cosmological data. In this case, reactor antineutrino experiments offer an ideal place to look for signatures of sterile neutrinos due to their impact on neutrino flavor transitions. In this work, we show that the high-precision data of the Daya Bay experiment constrain the 3+1 neutrino scenario imposing upper bounds on the relevant active-sterile mixing angle sin2 2θ14 ≲ 0.06 at 3σ confidence level for the mass-squared difference Δm412 in the range (10−3, 10−1) eV2. The latter bound can be improved by six years of running of the JUNO experiment, sin2 2θ14 ≲ 0.016, although in the smaller mass range Δm412 ∈ (10−4, 10−3) eV2. We have also investigated the impact of sterile neutrinos on precision measurements of the standard neutrino oscillation parameters θ13 and Δm312 (at Daya Bay and JUNO), θ12 and Δm212 (at JUNO), and most importantly, the neutrino mass hierarchy (at JUNO). We find that, except for the obvious situation where Δm412 ≲ Δm312, sterile states do not affect these measurements substantially.