Study of neutrino oscillation parameters at the INO-ICAL detector using event-by-event reconstruction

We present the reach of the proposed INO-ICAL in measuring the atmospheric-neutrino-oscillation parameters $$\theta _{23}$$θ23 and $$\varDelta m^2_{32}$$Δm322 using full event-by-event reconstruction for the first time. We also study the fluctuations arising from the low event statistics and their effect on the precision measurements and mass-hierarchy analysis for a 5-year exposure of the 50 kton ICAL detector. We find a mean resolution of $$\varDelta \chi ^2 \approx 2.9$$Δχ2≈2.9, which rules out the wrong mass hierarchy of the neutrinos with a significance of approximately $$1.7\sigma $$1.7σ. These results on mass-hierarchy are similar to those presented in earlier studies that approximated the performance of the ICAL detector.