Speaker
Dr.
Vicent Mateu
(IFIC)
Description
For the e+e- C-parameter we use soft-collinear effective theory to derive a factorization theorem, and then compute the cross section at N3LL + O(alphas^3). Differences with Thrust are highlighted. Our result holds for C in the peak, tail, and far tail regions, and we treat hadronization effects using a universal nonperturbative soft function defined in field theory. We analyze all available C-parameter tail data and obtain a global fit for alphas(mZ) and one nonperturbative parameter Omega1^C with chi^2/dof close to 1. These C-parameter results for alphas(mZ) and Omega1 are in excellent agreement with earlier results from thrust. Furthermore, for the first time we include hadron mass effects in the analysis of thrust and C-parameter experimental data.
Primary author
Dr.
Vicent Mateu
(IFIC)
