Improved electron reconstruction in ATLAS using the Gaussian Sum Filter-based model for bremsstrahlung

The behavior of high-energy electrons in the ATLAS Inner Detector is dominated by radiative energy losses (bremsstrahlung)as they traverse matter. These can be significant considering the substantial amount of material that the Inner Detector contains and can give rise to deviations from the original charged particle's path as it propagates through the magnetic field. As a result, significant inefficiencies, both during the electron trajectory reconstruction and in the determination of the corresponding track parameters in the bending plane, can be observed. In this note, we present a modification of the electron reconstruction in ATLAS that uses track refitting with the Gaussian Sum Filter (GSF) algorithm, with the aim of improving the estimated electron track parameters. The performance of this new scheme is compared to that of the existing standard electron reconstruction, for electron transverse energies between 7 GeV and 80 GeV.