NNLO leptonic and hadronic corrections to Bhabha scattering and luminosity monitoring at meson factories

Virtual fermionic N-f = 1 and N-f = 2 contributions to Bhabha scattering are combined with realistic real corrections at next-to-next-to-leading order in QED. The virtual corrections are determined by the package BHA-NNLO-HF, and real corrections with the Monte Carlo generators BHAGEN-1PH, HELAC-PHEGAS AND EKHARA. Numerical results are discussed at the energies of and with realistic cuts used at the Phi factory DA Phi NE, at the B factories PEP-II and KEK, and at the charm/tau factory BEPC II. We compare these complete calculations with the approximate ones realized in the generator BABAYAGA@NLO used at meson factories to evaluate their luminosites. For realistic reference evern selections we find agreement for the NNLO leptonic and hadronic corrections within 0.07% or better and conclude that they are well accounted for in the generator by comparison with the present experimental accuracy.