Abstract
The standard picture of the loop expansion associates a factor of with each loop, suggesting that the tree diagrams are to be associated with classical physics, while loop effects are quantum mechanical in nature. We discuss counterexamples wherein classical effects arise from loop diagrams and display the relationship between the classical terms and the long range effects of massless particles.
- Received 13 July 2004
DOI:https://doi.org/10.1103/PhysRevLett.93.201602
©2004 American Physical Society