Bremsstrahlung mechanism of heavy vector meson production

Vector mesons as φ, ω, and J/Ψ with JPC=1-- are produced at colliding electron-positron high energy beams through the annihilation and the scattering channels. We consider here the scattering mechanism, namely, the creation of a vector meson in the fragmentation region of one of the initial leptons. It corresponds to the kinematics where the vector meson is emitted close to the direction of one of the colliding leptons, while the direction of the other lepton remains close to the initial one. The annihilation channel contribution is enhanced by the initial hard photon emission mechanism. It occurs in the kinematical region where the final particles are emitted at large angles and plays the role of background. Differential distributions of the energy fraction and of the transverse component of the vector meson are calculated. The relevant formalism and the numerical estimations are presented.