On the Sudakov form factor, and a factor of two

2020/01/14 by Stefano Forte, Forte, Stefano
Engineering · Physics and Astronomy · #Computer science #Engineering #FOS: Physical sciences #Factor (programming language) #Fermion #Form factor (electronics) #Gravitational singularity #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Nuclear physics research studies #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Shell (structure) #Theoretical physics

paper · pdf · doi:10.48550/arxiv.2001.04995

openalex publication_date 2020/01/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

I answer a question that Roman Jackiw asked me, and I draw some lessons from the answer. The question is: why is the Sudakov form factor larger by a factor of two, if computed for off-shell fermions, in comparison to the on-shell case? The answer sheds some light on the interplay between infrared and collinear singularities -- and the importance of factors of two.

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