[IP2I Seminar] Particle Phenomenology - Joe Sato: An Analytic Prescription for t-channel Singularities

lundi 7 juil. 2025, 14:00 → 15:00 Europe/Paris

Dirac/RdC-Amphithéâtre (IP2I)

The t-channel singularity is a divergence in the scattering amplitude which occurs when a stable particle propagating in t-channel scattering process becomes an on-shell state. It is in a sharp contrast with s- channel type singularity which is always regulated by a decay width in s-channel particle. Such situations appear either in the system of collider experiments or in the context of the cosmological particle production. No scheme which is generally applicable is known. In this talk, I introduce a new formulation to identify and remove the source of the divergence. The scheme is fully analytical and various applications can be expected. Using concrete examples, I explain what are these singularities and I will present our method for t-channel singularity.