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arXiv · 2202.05038

Improving CP Measurement with THEIA and Muon Decay at Rest

Shao-Feng Ge·Chui-Fan Kong·Pedro Pasquini
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Abstract

We explore the possibility of using the recently proposed THEIA detector to measure the $\bar \nu_\mu \rightarrow \bar \nu_e$ oscillation with neutrinos from a muon decay at rest ($\mu$DAR) source to improve the leptonic CP phase measurement. Due to its intrinsic low-energy beam, this $\mu$THEIA configuration ($\mu$DAR neutrinos at THEIA) is only sensitive to the genuine leptonic CP phase $\delta_D$ and not contaminated by the matter effect. With detailed study of neutrino energy reconstruction and backgrounds at the THEIA detector, we find that the combination with the high-energy DUNE can significantly reduce the CP uncertainty, especially around the maximal CP violation cases $\delta_D = \pm 90^\circ$. Both the $\mu$THEIA-25 with 17kt and $\mu$THEIA-100 with 70kt fiducial volumes are considered. For DUNE + $\mu$THEIA-100, the CP uncertainty can be better than $8^\circ$.

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Shao-Feng Ge, Chui-Fan Kong, Pedro Pasquini. 2022-02-10. Improving CP Measurement with THEIA and Muon Decay at Rest. https://doi.org/10.1140/epjc/s10052-022-10478-8

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