2002/03/05 by H. Arthur Weldon · 2 citations
Mathematics · Physics and Astronomy · #Quantum Chromodynamics and Particle Interactions #Spectral Theory in Mathematical Physics #Theoretical and Computational Physics #hep-ph
paper · pdf · doi:10.1103/physrevd.65.076010
published as Phys.Rev. D65 (2002) 076010 · 17 pages
arxiv created 2002/03/05 · openalex publication_date 2002/04/05 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The analytic properties in the energy variable k0 of finite-temperature self-energies are investigated. A typical branch cut results from n particles being emitted into the heat bath and n^\ensuremath' being absorbed from the heat bath. There are three main results: First, in addition to the branch points at which the cuts terminate, there are also branch points attached to the cuts along their length. Second, branch points at k0=\ifmmode±\else\textpm\fik are ubiquitous and for massive particles they are essential singularities. Third, in a perturbative expansion using free particle propagators or in a resummed expansion in which the propagator pole occurs at a real energy, the self-energy will have a branch point at the pole location.