Reactor Antineutrino Oscillations at Super-Kamiokande

SuperKamiokande (SK) doped with gadolinium has the capability to efficiently identify electron-antineutrinos through inverse beta-decay. Given the size of SK and the number of nuclear reactors in its vicinity, we argue that SK can observe the oscillations of reactor antineutrinos driven by the so-called solar mass-squared difference $\mathrm{\Delta }{m}_{21}^2$. After only one year of data taking, we estimate that SK can measure $\mathrm{\Delta }{m}_{21}^2$ with enough precision to help inform the current small tension between existing results from KamLAND and solar neutrino experiments.