| Description |
Infrared renormalon singularities make the perturbative predictions ambiguous at the power correction level. These ambiguities are compensated by non-perturbative contributions. Thus ambiguities in perturbative corrections give information about non perturbative effects. We discuss power corrections to event shape variables at e+e- collider such as thrust, C-parameter etc., and show how the leading power corrections can be obtained easily using soft gluon approximation to the matrix element and approximating the definition of the shape variables in the same limit.
|