Cross sections ofe+e−→γVVande+e−→γγV

Abstract

Cross sections of the e{sup +}e{sup -} annihilate into one photon and two vector mesons, such as J/{psi}{rho}, J/{psi}{phi}, and {rho}{phi} at the center of mass energy {radical}(s)=10.58 GeV are calculated. These shed light on the measurement of the e{sup +}e{sup -} annihilation cross section via radiative return in B factories. At another center of mass energy {radical}(s)=3.097 GeV, namely, the J/{psi} resonance peak, the cross sections for the processes e{sup +}e{sup -}{yields}{gamma}VV and e{sup +}e{sup -}{yields}{gamma}{gamma}V (with V being {rho}, {omega}, or {phi}) are calculated with similar methods. These calculations give an estimation of the background levels in the study of radiative or double radiative decays of J/{psi}.