Sterile Neutrino Inclusion Resolves the Octant Degeneracy in the Presence of Resonant Matter Effect

Results of experiments like LSND and MiniBooNE hint toward the possible presence of an additional eV scale sterile neutrino. The addition of a sterile neutrino will significantly impact the standard three flavor neutrino oscillations in particular, giving rise to additional degeneracies due to new sterile parameters. Our work investigates how sterile neutrino influences the sensitivity to determine the octant of \(\theta _{23}\) . We have analyzed the sensitivity to the octant of \(\theta _{23}\) at very long baselines where the resonance matter effect comes into play. Our analytical expressions of the neutrino oscillation probabilities using \(\Delta _{21}=0\) approximation help us explain the same. We have determined the octant sensitivity using atmospheric and accelerator neutrinos in the presence of a non-magnetized Liquid Argon Time Projection Chamber (LArTPC) detector as well as the inclusion of a process to differentiate between \(\mu ^{+},\mu ^{-}\) using muon capture and decay.