Speaker
Description
Determining the leptonic CP-violating phase $\delta_{\rm CP}$, the atmospheric mixing angle $\theta_{23}$, and the mass-squared difference $\Delta m^2_{31}$ with high precision is a central goal of current and next-generation long-baseline neutrino experiments. In this work, we investigate the fundamental information content of three-flavor neutrino oscillations within the framework of quantum estimation theory. Treating the propagating neutrino as an evolving pure quantum state, we analyze the quantum Fisher information (QFI) and the quantum Fisher information matrix (QFIM) associated with $\theta_{23}$, $\delta_{\rm CP}$, and $\Delta m^2_{31}$. We study the dependence of the QFI on the baseline-to-energy ratio $L/E$, revealing distinct sensitivity structures for the three oscillation parameters, and examine the role of parameter correlations in determining the multiparameter quantum Cramér–Rao bound. We further investigate parameter degeneracies in neutrino oscillation probabilities and demonstrate that probability-degenerate parameter sets need not correspond to indistinguishable quantum states. Using quantum fidelity, we identify distinct quantum-state characteristics among degenerate ($\theta_{23}$, $\delta_{\rm CP}$) solutions that remain inaccessible at the probability level. Our results highlight quantum estimation theory as a complementary framework for assessing the ultimate precision of neutrino oscillation measurements and for uncovering quantum information hidden by probability-based analyses.