Biprobability approach to CP phase degeneracy from non-standard neutrino interactions

Abstract

Non-standard interactions (NSI) between neutrinos and matter at long-baseline experiments could make determination of the CP-violating phase ${\delta }_{13}$ ambiguous due to interference with additional complex phases. Such degeneracies are often studied in the context of specific experiments and a few parameter choices, leaving it unclear how to extract a general understanding of when two sets of parameters may be degenerate or how different types of experiments in principle combine to lift such a degeneracy. This work complements detailed simulations of individual experiments by showing how underlying parameters relate to degeneracies as represented on a biprobability plot. We show how a range of energies near the oscillation maximum ${\Delta }_{31}=\pi /2$ separates some degenerate probabilities along the CP-conserving direction of biprobability space according to ${\delta }_{+}\equiv {\delta }_{13}+{\delta }_{e\tau }$, while near ${\Delta }_{31}=3\pi /2$ degenerate probabilities are separated along the CP-violating direction according to ${\delta }_{e\tau }$. We apply this to the experimental hints that suggest ${\delta }_{13}\sim -\pi /2$ to see that this could also be consistent with ${\delta }_{13},{\delta }_{e\tau }=0$ or $\pi$. The baseline and energy range characteristic of DUNE provides some resolution, but a further improvement comes from beams a few degrees off-axis at $\gtrsim 1000$ km baselines, including some proposed sites for T2HKK.

arXiv commentVersion accepted & to appear in Nuclear Physics B

References in corpus (36)

• Golden measurements at a neutrino factory
• Breaking Eight-fold Degeneracies in Neutrino CP Violation, Mixing, and Mass Hierarchy
• Status of non-standard neutrino interactions
• Exploring Neutrino Mixing with Low Energy Superbeams
• $\mathcal{N}=1$ supersymmetric indices and the four-dimensional A-model
• Non-Standard Neutrino Interactions with Matter from Physics Beyond the Standard Model
• Non standard neutrino interactions
• Leptonic CP violation
• Solar neutrinos as probes of neutrino-matter interactions
• CP Violation and Matter Effect in Long Baseline Neutrino Oscillation Experiments
• Non-Standard Neutrino Interactions and Neutrino Oscillation Experiments
• Non-standard Neutrino Interactions at DUNE
• Measurement of neutrino and antineutrino oscillations by the T2K experiment including a new additional sample of ${\nu }_e$ interactions at the far detector
• New CP Violation in Neutrino Oscillations
• Atmospheric neutrinos as probes of neutrino-matter interactions
• Lepton Flavor Violating Non-Standard Interactions via Light Mediators
• Non-Standard Interactions in propagation at the Deep Underground Neutrino Experiment
• Degeneracies in long-baseline neutrino experiments from nonstandard interactions
• Probing CP violation signal at DUNE in presence of non-standard neutrino interactions
• A combined study of source, detector and matter non-standard neutrino interactions at DUNE
• Degeneracy between ${\theta }_{23}$ octant and neutrino non-standard interactions at DUNE
• Nonstandard neutrino interactions at DUNE, T2HK and T2HKK
• Perturbation Theory of Neutrino Oscillation with Nonstandard Neutrino Interactions
• Non-standard interactions spoiling the CP violation sensitivity at DUNE and other long baseline experiments
• Hints for leptonic CP violation or New Physics?
• Sensitivity of the T2HKK experiment to the non-standard interaction
• Can nonstandard interactions jeopardize the hierarchy sensitivity of DUNE ?
• CP Violation in the Lepton Sector and Implications for Leptogenesis
• Sensitivities and synergies of DUNE and T2HK
• Non-Standard Interactions at a Neutrino Factory: Correlations and CP violation
• Resolving CP Violation by Standard and Nonstandard Interactions and Parameter Degeneracy in Neutrino Oscillations
• 3-flavor and 4-flavor implications of the latest T2K and NO$\nu$A electron (anti-)neutrino appearance results
• Neutrino vs. Antineutrino Oscillation Parameters at DUNE and Hyper-Kamiokande
• The Discovery reach of $CP$ violation in neutrino oscillation with non-standard interaction effects
• Probing the leptonic Dirac CP-violating phase in neutrino oscillation experiments
• False Signals of CP-Invariance Violation at DUNE

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• CP-Violating Neutrino Non-Standard Interactions in Long-Baseline-Accelerator Data
• Non-standard neutrino interactions as a solution to the NO$\nu$A and T2K discrepancy
• General Neutrino Interactions at the DUNE Near Detector
• Neutrino mass ordering obscured by non-standard interactions
• The Impact of Different Parameterizations on the Interpretation of CP Violation in Neutrino Oscillations
• Detecting CP Violation in the Presence of Non-Standard Neutrino Interactions
• The Sensitivity of DUNE in Presence of Off-Diagonal Scalar NSI Parameters
• ${\delta }_{CP}$-free constraints on NSI parameters ${\epsilon }_{e\mu }$ and ${\epsilon }_{e\tau }$ using high-purity ${\nu }_{\mu }$ CC events at IceCube DeepCore