Revisiting non-perturbative effects in the jet broadenings

Abstract

We show that taking into account the interplay between perturbative and non-perturbative effects, the power-suppressed shift to the broadening distributions becomes B dependent, and the non-perturbative contribution to the mean values becomes proportional to 1/(Q\sqrt{\as(Q)}). The new theoretical treatment greatly improves the consistency of the phenomenology with the notion of the universality of confinement effects in jet shapes.

Comments: 44 pages, 8 .eps figures; uses amsmath. This updated version includes the revised value for the Milan factor, which follows from the correction of a mistake in hep-ph/9707532