Tau Neutrino Studies at the ICAL detector in INO

We present the results of the first simulation based analysis of tau neutrino events at the proposed magnetized Iron Calorimeter (ICAL) detector in the India Based Neutrino Observatory (INO) facility. We show that the detection capability of tau neutrinos is more than 3σ confidence level for a period of 10 years. This analysis was performed by studying the combined sample of tau events from Charged Current (CC) tau neutrino (and anti-neutrino) interactions in the detector and the Neutral Current (NC) background events produced from the interactions of neutrinos of all flavors. The hadronically decaying taus from the CC tau events (which comprise 67%) of the tau events) and the NC events produce hadrons predominantly and can be separated from the dominant CC νμ interactions (so-called standard muon events which are the main focus of ICAL physics) where the final state muon will leave long curved tracks due to the magnetized iron plates in ICAL in addition to hadron showers. We also show that these combined hadronic events are sensitive to the neutrino oscillation parameters sin2θ23 (including its octant) and Δm2 even with the inclusion of several possible systematic uncertainties. Since the origin of the standard muon and hadronic events are both from the same atmospheric electron and muon neutrinos, they have common systematic errors. We show that there is a significant improvement in the precision to which these oscillation parameters can be measured when the standard muon events are combined with the hadronic events arising from the CC tau and NC interactions.