Cosmic Muon Induced EM Showers in NO$\nu$A Detector

Being a \(\nu _e\) appearance experiment, NO\(\nu \)A finds signal \(\nu _e\) events by detecting electrons in the final state of (\(\nu _e\)-CC) interaction. This requires correct modeling and reconstruction of electrons. The biggest background to \(\nu _e\)-CC signal events is from \(\nu _\mu \)-NC events where \(\pi ^0\) from hadronic showers decay into energetic photons which can fake electron-induced electromagnetic (EM) showers. To reduce the background, the particle identification algorithm should be able to correctly identify an EM shower as either from an electrons or from a \(\pi ^0\). Intrinsic beam \(\nu _e\) events and \(\nu _\mu \)-CC events where muon track is very short, also contribute to the background. Cosmic muons produce EM showers through interaction with detector media or via decay into electrons. These showers, once being isolated, can provide a test sample of pure EM showers. EM shower modelling and reconstruction efficiency in the NO\(\nu \)A detectors can be better understood and quantified using such a sample.