Radiative corrections to neutral-vector-meson production in e(+)e(-) annihilation followed by meson decay into a lepton pair

To describe the total cross sections for processes of the type e(+) + e(-) --> V --> l(+) + l(-), the Breit-Wigner formula is generalized with allowance for various radiative corrections of order a and for a finite energy resolution Delta E-gamma. The radiative correction associated with the emission of virtual, soft, and bremsstrahlung photons by final leptons is estimated and shown to depend on the value of their maximum noncollinearity angle Delta Theta(max). This correction reaches a maximum for Delta Theta(max) --> 0.