Leptonic CP Phase Determination from Fisher Information in T2K and NOνA
Abstract
The precise determination of the leptonic CP phase δCP remains one of the central objectives of current and future long-baseline (LBL) neutrino oscillation experiments. Quantum estimation theory provides a natural framework to quantify the ultimate precision limits for estimating physical parameters encoded in quantum states. In this work, we employ the quantum Fisher information to investigate how much information about δCP is intrinsically encoded in neutrino states and how efficiently it is extracted in present LBL experiments such as T2K and NOνA. We first analyze the intrinsic quantum sensitivity of neutrino and antineutrino states and demonstrate how matter effects generate a neutrino mass-ordering dependent information structure. To compare the intrinsic information content of the quantum state with the information experimentally accessible through flavor measurements, we compute the event-level Fisher information from reconstructed event spectra using Poisson statistics including backgrounds and systematics. We find that both experiments extract only a small fraction of the total information available in the underlying quantum state. This extraction efficiency becomes particularly suppressed near maximally CP-violating regions, where the reconstructed event spectra exhibit reduced sensitivity to small variations in δCP. We also apply the same framework to the reactor mixing angle θ13, providing a benchmark for comparison with the estimation of δCP. Our analysis provides a complementary information-theoretic perspective on precise estimation of oscillation parameters in LBL neutrino experiments.
Related
- Fisher Information Dynamics: A Kinematic Framework for Phase Space Ordering with Applications to Shock Layers and Turbulence
- Model-Independent Determination of Intrinsic Leptonic CP Violation
- Residual Fisher Information in Measurement-Error Uncertainty
- Evaluation of the quantum Fisher information for large systems via an ancilla
- Rapid Uncertainty Quantification on a Latent Field using Fisher Information
BibTeX
@misc{chundawat2026leptonic,
title = {{Leptonic CP Phase Determination from Fisher Information in T2K and NO$ν$A}},
author = {Neetu Raj Singh Chundawat and Luis A. Delgadillo and Yu-Feng Li},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2605.30404},
eprint = {2605.30404},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.30404},
}
RIS
TY - UNPB
TI - Leptonic CP Phase Determination from Fisher Information in T2K and NOνA
AU - Neetu Raj Singh Chundawat
AU - Luis A. Delgadillo
AU - Yu-Feng Li
PY - 2026
DA - 2026/11/04
PB - arXiv
DO - 10.48550/arxiv.2605.30404
UR - https://arxiv.org/abs/2605.30404
AB - The precise determination of the leptonic CP phase δ_CP remains one of the central objectives of current and future long-baseline (LBL) neutrino oscillation experiments. Quantum estimation theory provides a natural framework to quantify the ultimate precision limits for estimating physical parameters encoded in quantum states. In this work, we employ the quantum Fisher information to investigate how much information about δ_CP is intrinsically encoded in neutrino states and how efficiently it is extracted in present LBL experiments such as T2K and NOνA. We first analyze the intrinsic quantum sensitivity of neutrino and antineutrino states and demonstrate how matter effects generate a neutrino mass-ordering dependent information structure. To compare the intrinsic information content of the quantum state with the information experimentally accessible through flavor measurements, we compute the event-level Fisher information from reconstructed event spectra using Poisson statistics including backgrounds and systematics. We find that both experiments extract only a small fraction of the total information available in the underlying quantum state. This extraction efficiency becomes particularly suppressed near maximally CP-violating regions, where the reconstructed event spectra exhibit reduced sensitivity to small variations in δ_CP. We also apply the same framework to the reactor mixing angle θ_13, providing a benchmark for comparison with the estimation of δ_CP. Our analysis provides a complementary information-theoretic perspective on precise estimation of oscillation parameters in LBL neutrino experiments.
ER -