Measuring the sterile neutrino CP phase at DUNE and T2HK

Sandhya Choubey,Dipyaman Pramanik,Debajyoti Dutta

doi:10.1140/epjc/s10052-018-5816-y

Sandhya Choubey, Dipyaman Pramanik + Show 1 more

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https://doi.org/10.1140/epjc/s10052-018-5816-y

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Abstract

The CP phases associated with the sterile neutrino cannot be measured in the dedicated short-baseline experiments being built to test the sterile neutrino hypothesis. On the other hand, these phases can be measured in long-baseline experiments, even though the main goal of these experiments is not to test or measure sterile neutrino parameters. In particular, the sterile neutrino phase delta _{24} affects the charged-current electron appearance data in long-baseline experiment. In this paper we show how well the sterile neutrino phase delta _{24} can be measured by the next-generation long-baseline experiments DUNE, T2HK (and T2HKK). We also show the expected precision with which this sterile phase can be measured by combining the DUNE data with data from T2HK or T2HKK. The T2HK experiment is seen to be able to measure the sterile phase delta _{24} to a reasonable precision. We also present the sensitivity of these experiments to the sterile mixing angles, both by themselves, as well as when DUNE is combined with T2HK or T2HKK.

Highlights

Neutrino oscillation physics has reached precision era
In the same section we provide the details of the DUNE, T2HK and T2HKK experiments
There are a number of observational hints that support the existence of neutrino oscillations at short baselines

Summary

Introduction

Even though neutrino oscillation with three-generations is well established, there are some hints of neutrino oscillations at a higher frequency corresponding to a mass-squared difference m2 ∼ 1 eV2 [13]. LSND experiment [14,15] in Los. Alamos, USA, first showed evidence for such oscillations, where a νμ beam was sent to a detector and the observations showed a 3.8σ excess in the positrons, which could be explained in terms of νμ → νe oscillations. For the L and E applicable for the LSND experiment, this oscillation corresponds to a mass-squared difference of m2 ∼ 1 eV2. MiniBooNE did not find any significant excess in their neutrino mode, they reported some excess in the antineutrino mode consistent with the LSND result. Apart from these, MiniBooNE reported some excess in the low energy bins for both neutrino and antineutrino appearance channels, but these cannot be explained in terms of neutrino flavour oscillations. Ln addition to the mixing angles θ12, θ23 and θ13 which appear 2 31 and m221, 6 mixing angles and 3 phases. ln addition to the mixing angles θ12, θ23 and θ13 which appear

We define m

Sterile neutrino mixing and simulation

Measurement of the sterile phases

Measurement of the mixing angles

Findings

Conclusions