ISSN - 0094243X, AIP Conference Proceedings, 2004, vol. 717, p. 49-54
Initial State Radiation Study at ϒ(4 S) in BaBar
© 2004 American Institute of Physics. An analysis of the processes with initial state radiation (ISR) has been performed using 90 fb -1 of BABAR data. The selection of μ + μ - and multiâ hadron final states has been demonstrated accompanied with the detected ISR photon. The invariant mass of hadronic final state determines the virtual photon energy and data can be compared with direct e + e - cross sections. The present BABAR data are already competitive with e + e - machine data in 0.28-3.0 GeV energy range and demonstrate many interesting details usefull for low energy hadron spectroscopy. In addition to light meson spectroscopy these data can be used for calculation of R-the ratio of e + e - → hadrons cross section to e + e - → μ + μ - -and thereby to impact the (g-2) μ measurement. The ISR technic gives an access to J/ψ production. The J/ψ decays to μμ, 4π, 2K2π and 4K have been selected and new preliminary measurements of branching ratios performed with comparable or typically better accuracy than PDG.