$n\sigma^{\textrm{TPC}}_{e^\pm}$ distribution without (black) and with (green) EMCal electron identification cuts of $E/p$ and $\sigma_{\rm long}^{2}$. Electrons form a Gaussian distribution centered around zero, indicated by the gray dashed line. The signal and background selection windows considered for the following $E/p$ plots are indicated by the red and blue shaded area, respectively. The distributions are shown for various event triggers in pp collisions at $\sqrt{s}=$ 13 TeV in different $p_{\rm T}$ intervals.