In this paper, we investigate the sensitivities of the upcoming long-baseline neutrino experiments P2SO and T2HKK to the long-range force (LRF). In the context of these two experiments, our objective is to study (i) their capabilities to put bounds on the LRF parameters as well as on constraining the mass and coupling strength of the new gauge boson, which gives rise to LRF due to matter density in Sun and (ii) the effect of LRF in the measurement of standard oscillation parameters. In our study, we find that among the different neutrino experiments, the best bounds on the LRF parameters including mass of the new gauge boson and its coupling strength will come from the P2SO experiment. Our study also shows that LRF has non-trivial effect on the determination of the standard neutrino oscillation parameters except the precision of $$ \Delta {m}_{31}^2 $$ ∆ m 31 2 . For this parameter, the precision remains unaltered in the presence of LRF for both these experiments.

Motivated by the persistent short-baseline anomalies that hint at the possible existence of physics beyond the standard three-flavor paradigm, we study the phenomenology of light sterile neutrinos in the minimal (3 + 1) framework using two future experiments: the MuOn-decay MEdium-baseline NeuTrino beam experiment (MOMENT) and the Deep Underground Neutrino Experiment (DUNE). We place constraints on active–sterile mixing parameters, probe CP-violation discovery potential, and examine correlations between the standard Dirac CP phase and the additional CP phases arising from active–sterile mixing to quantify phase degeneracies. We present exclusion limits and demonstrate the crucial role of the near detector in improving sensitivities by one or two orders of magnitude compared to a configuration with only the far detector. We find that the presence of sterile neutrinos can reduce the CP-violation sensitivity in long-baseline neutrino oscillation experiments. For large sterile mass splittings, the rapid oscillations average out, leading to strong parameter degeneracies in DUNE. In contrast, MOMENT retains strong sensitivity to CP violation and efficiently disentangles the standard and sterile CP phases. Our results highlight the strong complementarity between DUNE and MOMENT and show that their combined capabilities provide a powerful test of the light sterile neutrino hypothesis in regions of the parameter space that remain weakly constrained by current data.

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 $$\eta _{e\mu }$$ η e μ and $$\eta _{e\tau }$$ η e τ , we obtained larger mass ordering and octant sensitivities as compared to the standard three flavour scenario. For the parameter $$\eta _{\mu \tau }$$ η μ τ , the mass ordering sensitivity and the precision of $$\Delta m^2_{31}$$ Δ m 31 2 deteriorated compared to the standard scenario. Our results also showed that the sensitivities were significantly influenced by the phases of the off-diagonal parameters.

A bstract: We compare the sensitivity of the upcoming long-baseline neutrino experiments Protvino to Super-ORCA (P2SO) and the Deep Underground Neutrino Experiment (DUNE) to non-unitarity (NU) of the leptonic mixing matrix in a model-independent framework. NU can arise in theories beyond the Standard Model that include heavy neutral leptons. These effects can modify neutrino oscillation probabilities and introduce new sources of CP violation, which may affect precision measurements of neutrino parameters. We find that DUNE provides stronger bounds on α ₁₁ and | α ₂₁ |, while P2SO shows better sensitivity to α ₂₂ and α ₃₃ , mainly due to its longer baseline and stronger matter effects. Our results show that DUNE (P2SO) will be able to improve the current bounds of α ₁₁ ( α ₃₃ ). We further examine correlations with standard oscillation parameters and quantify the impact of NU on mass hierarchy, octant, and CP-violation sensitivities. Our results show that these sensitivities depend upon NU in a non-trivial way interconnecting the parameter degeneracies and matter effects. Our results demonstrate the complementarity of P2SO and DUNE in probing NU and show that NU can significantly influence next-generation precision oscillation studies.