Determination of Ionization Energy Loss of Electron-Positron Pair in Multi-GeV Region

The suppression of ionization energy loss owing to the Chudakov effect is discussed using the opening angles of the electron-positron pairs from the GEANT4 simulation package. The expected Borsellino and Olsen angles for photon energies between 1-178 GeV were presented and compared with the simulated opening angles. The simulated opening angles of the electron-positron pair are mostly compatible with the Borsellino angle for energies below 30 GeV. The ionization-suppression effect was reproduced using known theoretical approaches and compared with the corresponding simulated results. The results showed that the GEANT4 simulation package is suitable for adopting the Chudakov effect in a simulation environment, with a dataset that provides theory-experiment consistency.