Effective predictions of event shapes: factorized, resummed and gapped angularity distributions

Using soft-collinear effective theory (SCET), which provides a unified for factorization, resummation of logarithms, and incorporation of universal functions in hard-scattering QCD cross-sections, we present a new prediction distributions in e(+)e(-) annihilation. Angularities tau(a) are an infinite class of which vary in their sensitivity to the substructure of jets in the final state, continuous parameter a < 2. We calculate angularity distributions for all a < 1 in the strong coupling alpha(s) and resum large logarithms in these distributions to-leading logarithmic (NLL) accuracy. Our expressions for the next-to-leading O(alpha(s)) partonic jet and soft functions in the factorization theorem for are given for the first time. We employ a model for the nonperturbative with a gap parameter which cancels the renormalon ambiguity in the We explore the relation between the SCET approach to resummation approaches in QCD, and discuss the advantages of the effective theory approach. In addition, we draw from the NLO calculations of the jet and soft functions and intuitive lesson about how factorization breaks down in the effective theory as a -> 1.