  The luminosity determination of electron-positron colliders operating in the
region of low-lying hadronic resonances (E_cm ~ 1-10 GeV), such as BEPC/BES,
DAPHNE, KEKB, PEP-II and VEPP-2M, requires the precision calculation of the
Bhabha process at large scattering angles. In order to achieve a theoretical
accuracy at a few 0.1% level, the inclusion of radiative corrections is
mandatory. The phenomenologically relevant effect of QED corrections is taken
into account in the framework of the Parton Shower (PS) method, which is
employed both for cross section calculation and event generation. To test the
reliability of the approach, a benchmark calculation, including exact O(alpha)
corrections and higher-order leading logarithmic contributions, is developed as
well and compared in detail with the PS predictions. The effect of O(alpha)
next-to-leading and higher-order leading corrections is investigated in the
presence of realistic event selections for the Bhabha process at the
Phi-factories. A new Monte Carlo generator for data analysis (BABAYAGA) is
presented, with an estimated accuracy of 0.5%. Possible developments aiming at
improving its precision and range of applicability are discussed.
