Sensitivity to neutrino decay with atmospheric neutrinos at the INO-ICAL detector

Sensitivity of the magnetized Iron Calorimeter (ICAL) detector at the proposed India-based Neutrino Observatory (INO) to invisible decay of the mass eigenstate nu(3) using atmospheric neutrinos is explored. A full three-generation analysis including Earth matter effects is performed in a framework with both decay and oscillations. The wide energy range and baselines offered by atmospheric neutrinos are shown to be excellent for constraining the nu(3) lifetime. We find that with an exposure of 500 kton - yr the ICAL atmospheric experiment could constrain the. 3 lifetime to tau(3)/m(3) > 1.51 x 10(-10) s/eV at the 90% C.L. This is 2 orders of magnitude tighter than the bound from MINOS. The effect of invisible decay on the precision measurement of theta(23) and vertical bar Delta m(32)(2)vertical bar is also studied.