Unambiguous determination of the neutrino mass hierarchy using reactor neutrinos

By Yu-Feng Li, Jun Cao, Yifang Wang, L. Zhan. 2013

253 citations recorded by the source corpus.

Determination of the neutrino mass hierarchy in a reactor neutrino experiment at the medium baseline is discussed. Observation of the interference effects between the Delta m(31)(2) and Delta m(32)(2) oscillations enables a relative measurement independent of the knowledge of the absolute mass-squared difference. With a 20 kton liquid scintillator detector of the 3%/root E (MeV) energy resolution, the Daya Bay II experiment at a baseline of similar to 50 km from reactors of total thermal power 36 GW can determine the mass hierarchy at a confidence level of Delta chi(2)(MH) similar to (10 divided by 12) (3 divided by 3.5 sigma) in six years after taking into account the real spatial distribution of reactor cores. We show that the unknown residual energy nonlinearity of the liquid scintillator detector has limited impact on the sensitivity due to the self-calibration of small oscillation peaks. Furthermore, an extra increase of Delta chi(2)(MH) similar or equal to 4(9) can be obtained, by including the precise measurement of the effective mass-squared difference Delta m(mu mu)(2) of expected relative error 1.5% (1%) from ongoing long-baseline muon neutrino disappearance experiments. The sensitivities from the interference and from absolute measurements can be cross-checked. When combining these two, the mass hierarchy can be determined at a confidence level of Delta chi(2)(MH) similar to (15 divided by 20) (4 sigma) in six years.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/64326351935caaec0a2165c8ebfe8428555e12e1

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Citations in the corpus

Flavor structures of charged fermions and massive neutrinos (2019, unknown): “It is aimed to measure the fine structure caused by ∆m(2)31 and ∆m 2 32 in the energy spectrum of reactor νe → νe oscillations driven by ∆m(2)21 [315, 316, 317].”
Invited review: Physics potential of the ICAL detector at the India-based Neutrino Observatory (INO) (2015, methodology): “Additionally, the medium-baseline reactor oscillation experiments [73], JUNO [74] and RENO-50 [75] aim to determine the hierarchy by performing a very precise, high statistics measurement of the neutrino energy spectrum.”
KM3MeT 2.0 Letter of intent for ARCA and ORCA (2016, methodology): “One option uses medium-baseline (∼50 km) reactor experiments such as JUNO and RENO-50, which probe the νe oscillation probability at low energies (∼MeV) where matter effects are negligible [103].”
Letter of intent for KM3NeT 2.0 (2016, methodology): “One option uses medium-baseline (∼50 km) reactor experiments such as JUNO and RENO-50, which probe the ne oscillation probability at low energies (∼MeV) where matter effects are negligible [102].”
Letter of Intent: The Precision IceCube Next Generation Upgrade (PINGU) (2014, background): “In the longer term, LBNE [20] could make a 3σ determination of the hierarchy for all values of δCP with less than 10 years of operation, while JUNO [21] in China and RENO50 [22] in South Korea are proposed to exploit reactor neutrino oscillations at mediumscale baselines of about 50-60 km to measure”
Quantifying the sensitivity of oscillation experiments to the neutrino mass ordering (2013, background): “[61] we find for a 4320 kt GW yr exposure T0 ≈ 11.”
JUNO physics and detector (2021, background): “The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass ordering as a primary physics goal [6, 7, 8, 9].”