Prospects of using opaque detectors in accelerator neutrino experiments

Opaque detectors are a recently proposed novel detector concept where an opaque scintillator aligned with wavelength-shifting fibers is used to enable the discrimination of electron neutrinos and antineutrinos with a rather low energy threshold. In this work, we explore the physics reach of using such a neutrino detection technique in accelerator-based neutrino oscillation experiments, where neutrino energies fall into the quasielastic regime. Simulating neutrino beams produced via the pion and muon decay, we investigate the prospects of using an opaque detector to search for CP violation in neutrino oscillations at medium and long baseline lengths. We find that a 75% fraction of $\delta_\text{CP}$ values could be reached for CP violation discovery by 3$\sigma$ confidence level or better when opaque detectors of 120 kton and 135 kton fiducial masses are used together with neutrino beams from J-PARC and MOMENT, respectively.