Resummed event-shape variables in DIS

Abstract

We complete our study of resummed event-shape distributions in DIS by presenting results for the class of observables that includes the current jet mass, the C-parameter and the thrust with respect to the current-hemisphere thrust axis. We then compare our results to data for all observables for which data exist, fitting for αs and testing the universality of non-perturbative 1/Q effects. A number of technical issues arise, including the extension of the concept of non globalness to the case of discontinuous globalness; singularities and non convergence of distributions other than in the Born limit; methods to speed up fixed-order Monte Carlo programs by up to an order of magnitude, relevant when dealing with many x and Q points; and the estimation of uncertainties on the predictions. © SISSA/ISAS 2002.