Acceptance times \TRD-trigger efficiency ($\epsilon_{\mathrm{TRD}}(p_{\mathrm{T}}^{\mathrm{e}})$) described by Eq. \ref{eq:slEff} for single electrons (left) and positrons (right) obtained from \TRD-triggered data (red solid circle), fitted with an error function (red line), and MC simulation (black open circle). See text for details.