Semi-numerical resummation of event shapes

Abstract

For many event-shape observables, the most difficult part of a resummation in the Born limit is the analytical treatment of the observable's dependence on multiple emissions, which is required at single logarithmic accuracy. We present a general numerical method, suitable for a large class of event shapes, which allows the resummation specifically of these single logarithms. It is applied to the case of the thrust major and the oblateness, which have so far defied analytical resummation and to the two-jet rate in the Durham algorithm, for which only a subset of the single logs had up to now been calculated.

29 pages, 7 figures. Version 2 adds some clarifications, a reference, as well as corrections to the subleading fixed-order coefficients and to figures 4 and 7