$E/p$ distributions for (a) electrons and (b) pions in pp collisions at $\sqrt{s}$ = 7 TeV, measured in the experiment (reddotted line), and compared to simulation (black full line). The samples of identified electrons and pions were obtained from reconstructed$\gamma$ conversions and $\Lambda$/$\Kzs$ decays, respectively. The simulation is a Pythia simulation with realistic detector configuration and full reconstruction.