Eur. Phys. J. C (1998) 5: 167-174
https://doi.org/10.1007/s100529800817

Theoretical physics

Perturbative thresholds in the physical region

Departamento de Física Aplicada, CINVESTAV-IPN, Apdo. Postal 73 “Cordernex”, 97310, Mérida, Yucatán, México

^* e-mail: abouzas@fis.cinvestav.mx

Received: 24 October 1997
Published online: 16 September 2013

Abstract

We consider unstable-particle scattering in the context of 3-body processes. We show that all partial-wave cross-sections are finite and positive, and the total cross-section is proportional to the transverse size of space in the region of on-shell particle exchange. We comment on the role of loop corrections.