Resummation of Large Logarithms within the Method of Effective Charges

Abstract

We show how the resummation of large logarithms can be incorporated into the method of effective charges. As an example, we apply this approach to the event shape variables thrust and heavy jet mass in e+e- annihilation. We find that, although the resummation creates problems with the behaviour of the efective charge in the 2-jet limit, smaller power corrections are required to fit the data compared to the standard approach. In addition, increasing the logarithmic accuracy reduces the size of the power corrections further. We also consider ``predicting'' the sub-leading logarithms in the MSbar scheme, obtaining surprisingly good results for the first few NLL terms.