Effective-vector-boson method for high-energy collisions

The effective-vector-boson method for high-energy collisions is precisely formulated by using factorization of the helicity amplitudes. All approximations related to kinematics are eliminated. Compact formulas for exact vector-boson distribution functions are derived. The on-mass-shell continuation of the vector-boson hard-scattering cross section is isolated and clarified. Improvements over the leading-logarithmic approximation are dramatic. Application of the new formalism to heavy-fermion and Higgs-boson production processes illustrates its extended range of accuracy and usefulness