Speaker
Description
A high-precision measurement of $\Delta m^2_{31}$ and $\theta_{23}$ is inevitable to estimate the Earth's matter effect in long-baseline experiments which in turn plays an important role in addressing the issue of neutrino mass ordering and to measure the value of CP phase in $3\nu$ framework. After reviewing the results from the current experiments and discussing the near-future sensitivities from IceCube Upgrade and KM3NeT/ORCA, we study the improvements in the precision of 2-3 oscillation parameters that the next-generation experiments, DUNE and T2HK, can bring either in isolation or combination. We highlight the relevance of the possible complementarity between DUNE and T2HK in determining the sensitivity towards the deviation from maximal mixing of $\theta_{23}$, excluding the wrong octant solution of $\theta_{23}$, and obtaining high precision on 2-3 oscillation parameters, as compared to their individual performances. We observe that for the current best-fit values of the oscillation parameters and assuming normal mass ordering (NMO), DUNE + T2HK can establish the non-maximal $\theta_{23}$ and exclude the wrong octant solution of $\theta_{23}$ at around 7$\sigma$ C.L. with their nominal exposures. We find that DUNE + T2HK can improve the current relative 1$\sigma$ precision on $\sin^{2}\theta_{23}~(\Delta m^{2}_{31})$ by a factor of 7 (5) assuming NMO. Also, we notice that with less than half of their nominal exposures, DUNE + T2HK can achieve the sensitivities that are expected from these individual experiments using their full exposures. We also portray how the synergy between DUNE and T2HK can provide better constraints on $(\sin^2\theta_{23}$ - $\delta_{\mathrm{CP}})$ plane as compared to their individual reach.
| Working Group | WG 1: Neutrino Oscillation Physics |
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