The time-like electromagnetic form factors of proton and charged kaon at high energies

Abstract

Abstract. The Initial State Radiation method in the BABAR experiment has been used to measure the time-like electromagnetic form factors at the momentum transfer from 9 to 42 (GeV/c) 2 for proton and from 7 to 56 (GeV/c) 2 for charged kaon. The obtained data show the tendency to approach the QCD asymptotic prediction for kaons and space-like form factor values for proton. The BABAR data have been used together with data from other experiments, to perform a model-independent determination of the relative phases between the single-photon and the three-gluon amplitudes in ψ → KK decays. The values of the branching fractions measured in the reaction e + e − → K + K − are shifted due to interference of resonant and nonresonant amplitudes. We have determined the absolute values of the shifts to be 5% for J/ψ and 15% for ψ(2S) decays.