Generalization of collinear factorization in perturbative QCD

Tuesday, 21 October 2025 at 10:45

We consider the most general factorization properties of scattering amplitudes in perturbative QCD in both collinear and collinear-soft limits. While scattering amplitudes obey strict collinear factorization (SCF) in the time-like collinear region to all perturbative orders, SCF is known to break in the so-called space-like collinear region. We generalize previously known results of SCF breaking to more than one collinear direction. We also extend our analysis to the simultaneous collinear-soft factorization.