Impact of scalar NSI with off-diagonal parameters at DUNE and P2SO

TL;DR

This work analyzes off-diagonal scalar NSI (SNSI) parameters in long-baseline neutrino experiments, focusing on complex off-diagonal entries $\eta_{\alpha\beta}=|\eta_{\alpha\beta}|e^{i\phi_{\alpha\beta}}$ that modify the neutrino mass matrix via $\delta M$. Using GLoBES with a modified probability engine, the authors simulate DUNE and P2SO (normal ordering, $m_1=10^{-5}$ eV) to derive bounds and study the impact on mass ordering, CP violation, octant sensitivity, and the precision of $\sin^2\theta_{23}$ and $\Delta m^2_{31}$, allowing one SNSI parameter at a time. They find that $|\eta_{e\mu}|$ and $|\eta_{e\tau}|$ can mimic the standard scenario within current $\Delta m^2_{31}$ ranges, while $|\eta_{\mu\tau}|$ behaves differently, with bounds strongly phase-dependent and CP sensitivity potentially washed out for certain $(|\eta_{\alpha\beta}|,\phi_{\alpha\beta})$ combinations. Phases play a crucial role in degeneracies and the overall sensitivity landscape, and combining DUNE with P2SO enhances constraints on SNSI. Overall, the study highlights the nontrivial phenomenology SNSI introduces and the necessity to account for such scalar-mediated interactions in the interpretation of future oscillation data.

Abstract

In this paper, we studied the impact of the off-diagonal SNSI parameters in the future long-baseline neutrino oscillation experiments DUNE and P2SO. In our analysis, we found that the sensitivities of these experiments altered in a very non-trivial way due to the presence of these parameters. Depending on the values of these parameters, they can either completely mimic the standard scenario or can wash out their CP sensitivity. For large values of parameters $η_{eμ}$ and $η_{eτ}$, we obtained larger mass ordering and octant sensitivities as compared to the standard three flavour scenario. For the parameter $η_{μτ}$, the mass ordering sensitivity and the precision of $Δm^2_{31}$ deteriorated compared to the standard scenario. Our results also showed that the sensitivities were significantly influenced by the phases of the off-diagonal parameters.

Figures (8)

• Figure 1: Allowed parameter space between $|\eta_{\alpha\beta}|$ and $\Delta m^2_{31}$ at 90% C.L. for DUNE and P2SO experiment.
• Figure 2: Top row: Sensitivity limit on the SNSI parameters for P2SO and DUNE experiments. Bottom row: Appearance probability as a function of energy in P2SO for three different cases.
• Figure 3: Allowed parameter space between SNSI parameter $|\eta_{\alpha\beta}|-\phi_{\alpha\beta}$ plane for P2SO and DUNE experiments at 90% C.L.
• Figure 4: Variation of mass ordering sensitivity as a function of $|\eta_{\alpha\beta}|$ for DUNE and P2SO experiments for different value of true phases.
• Figure 5: Variation of mass ordering sensitivity as a function of $|\eta_{\alpha\beta}|$ with different minimization conditions over parameters for $\phi^{\rm true}_{\alpha \beta}=0$ considering DUNE experiment.