Cancellation of Infrared Divergences at Finite Temperature

✍ Scribed by D. Indumathi

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 483 KB
• Volume: 263
• Category: Article
• ISSN: 0003-4916
• DOI: 10.1006/aphy.1997.5758

✦ Synopsis

We consider a typical hard scattering process in a heat bath of photons and electrons at temperature, T, in finite temperature QED. We show that the infrared pieces of both the real and virtual parts of the cross section factorise; these can be exponentiated and cancel between each other to all orders in perturbation theory. Hence the Bloch Nordsieck theorem remains valid for such processes at non-zero temperature as well. We use the technique of Grammer and Yennie to give a prescription for the extraction of the infrared divergent parts and for the form of the finite remainder. Symmetry arguments are used to show the finiteness of new terms arising in the T{0 part of the computation.