Quantifying the sensitivity of oscillation experiments to the neutrino mass ordering

By Mattias Blennow, P. Coloma, Patrick Huber, T. Schwetz. 2013

165 citations recorded by the source corpus.

A bstractDetermining the type of the neutrino mass ordering (normal versus inverted) is one of the most important open questions in neutrino physics. In this paper we clarify the statistical interpretation of sensitivity calculations for this measurement. We employ standard frequentist methods of hypothesis testing in order to precisely define terms like the median sensitivity of an experiment. We consider a test statistic T which in a certain limit will be normal distributed. We show that the median sensitivity in this limit is very close to standard sensitivities based on Δχ2 values from a data set without statistical fluctuations, such as widely used in the literature. Furthermore, we perform an explicit Monte Carlo simulation of the INO, JUNO, LBNE, NOνA, and PINGU experiments in order to verify the validity of the Gaussian limit, and provide a comparison of the expected sensitivities for those experiments.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/67794190b793f28d41167b6f5eafb6ea043eb223

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In Nuclear and High Energy Physics

1. Y. Farzan
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7. Francesco Capozzi
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Citations in the corpus

• Invited review: Physics potential of the ICAL detector at the India-based Neutrino Observatory (INO) (2015, background): “AL and and scale it down to the desired exposure for the ˜2 analysis. The ICAL sensitivities presented here can then be interpreted as median sensitivities (in the frequentist sense), as described in [118]. Using 1000 years of data takes us closer to the ideal \Asimov" data set [119] that has n”
• Neutrino masses and mixings: Status of known and unknown 3ν parameters (2016, background): “Concerning hierarchy tests, it has been argued that the above Nσ prescription can still be used to assess the statistical difference between NH and IH with good approximation [17].”
• Long-baseline neutrino oscillation physics potential of the DUNE experiment (2020, unknown): “Studies have indicated that special attention must be paid to the statistical interpretation of neutrino mass ordering sensitivities [99–101] because the Δχ 2 metric does not follow the expected chi-square function for one degree of freedom, so the interpretation of the (cid:4) Δχ 2 as the…”
• Global constraints on absolute neutrino masses and their ordering (2017, methodology): “Following the general statistical arguments in [25], we use the Δχ(2) metric also to assess the relative likelihood of the two mass-ordering hypotheses,”
• Deep Underground Neutrino Experiment (DUNE), Far Detector Technical Design Report, Volume II: DUNE Physics (2020, background): “The interpretation of √ ∆χ2 has been discussed in [195, 196]; it may be interpreted as approximately equivalent to significance in σ for ∆χ2 > 1.”
• NuFit-6.0: updated global analysis of three-flavor neutrino oscillations (2024, unknown): “[43, 44], under certain conditions T will follow a Gaussian distribution with mean ± T 0 and standard deviation 2 √ T 0 , where T 0 is obtained as follows.”
• Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF (2015, background): “However, studies in [21, 22] show that, in the case of the mass hierarchy determination, the ∆χ2 metric does not follow the expected chi-squared function for one degree of freedom.”
• Neutrino Mass Ordering from Oscillations and Beyond: 2018 Status and Future Prospects (2018, methodology): “We will follow a Bayesian approach to model comparison (see previous work suggesting the Bayesian method as the most suited one for the mass ordering extraction in Qian et al., 2012 and Blennow, 2014)21, which makes use of the Bayesian evidence Z.”
• Letter of Intent: The Precision IceCube Next Generation Upgrade (PINGU) (2014, background): “The net impact of all of these changes is to reduce the estimated sensitivity to the hierachy to a level comparable to, but slightly below, the conservative end of the range estimated at the time of the Community Summer Study, and in agreement with external estimates [26, 24].”
• Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 1: The LBNF and DUNE Projects (2015, background): “However, studies in [21, 22] show that, in the case of the mass hierarchy determination, the ∆χ2 metric does not follow the expected chi-squared function for one degree of freedom.”