Speaker
Ashot Gasparyan
(Ruhr University Bochum)
Description
Any effective field theory relies on a certain power counting that allows one to perform a systematic expansion of calculated quantities in terms of some soft scales. However, a naive power counting can be violated due to the presence of various hard scales in the scheme. A typical example of such a scale is an ultraviolet regulator. This issue is particularly challenging when the interaction is nonperturbative. The power counting is expected to be restored in the course of renormalization, that is by redefining bare low energy constants in the effective Lagrangian. Whether this procedure works is not a priory obvious. We discuss various criteria of renormalizability and applications to the few-body physics.
Primary authors
Ashot Gasparyan
(Ruhr University Bochum)
Evgeny Epelbaum
(Ruhr University Bochum)
