e+e- results from BABAR and their impact on the muon g-2 prediction

The BABAR collaboration has nearly completed a program of precise measurements of the cross sections for the dominant channels of e(+)e(-) --> hadrons from threshold to 3 GeV using the initial-state radiation (ISR) method, i.e. the measurement of the cross sections e(+)e(-) --> gamma hadrons with the energetic gamma detected at large angle to the beams. These data are used as input to vacuum polarization dispersion integrals, in particular the hadronic contribution to the muon g - 2 anomaly. In addition to the recently measured pi(+)pi(-) and K+K- cross sections, giving the dominant contribution, multihadronic channels have been investigated, with some recent examples presented here for the pi(+)pi(-)pi(+)pi(-), K+K-pi pi, KSKL, KSKL pi(+)pi(-), KSKS pi(+)pi(-) channels. The BABAR results have the best precision and cover for the first time almost all significant hadronic contributions below 2 GeV entering the muon g - 2 prediction.