Renormalons in effective field theories
- Department of Physics, University of Toronto, Toronto, M5S 1A7 (Canada)
- Department of Physics, University of California at San Diego, La Jolla, California 92093 (United States)
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)
We investigate the high-order behavior of perturbative matching conditions in effective field theories. These series are typically badly divergent, and are not Borel summable due to infrared and ultraviolet renormalons which introduce ambiguities in defining the sum of the series. We argue that, when treated consistently, there is no physical significance to these ambiguities. Although nonperturbative matrix elements and matching conditions are in general ambiguous, the ambiguity in any physical observable is always higher order in 1/{ital M} than the theory has been defined. We discuss the implications for the recently noticed infrared renormalon in the pole mass of a heavy quark. We show that a ratio of form factors in exclusive {Lambda}{sub {ital b}} decays (which is related to the pole mass) is free from renormalon ambiguities regardless of the mass used as the expansion parameter of heavy quark effective theory. The renormalon ambiguities also cancel in inclusive heavy hadron decays. Finally, we demonstrate the cancellation of renormalons in a four-Fermi effective theory obtained by integrating out a heavy colored scalar.
- Research Organization:
- Univ. of California (United States)
- DOE Contract Number:
- FG03-90ER40546
- OSTI ID:
- 44758
- Journal Information:
- Physical Review, D, Vol. 51, Issue 9; Other Information: PBD: 1 May 1995
- Country of Publication:
- United States
- Language:
- English
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