Factorization Approach for Top Mass Reconstruction at High Energies

Using effective theories for jets and heavy quarks it is possible to prove that the double differential top-antitop invariant mass distribution for the process ee → tt̄ in the resonance region for c.m. energies Q much larger than the top mass can factorized into perturbatively computable hard coefficients and jet functions and a non-perturbative soft function. For invariant mass prescriptions based on hemispheres defined with respect to the thrust axis the soft function can be extracted from massless jet event shape distributions. This approach allows in principle for top mass determinations without uncertainties from hadronization using the reconstruction method and to quantify the top mass scheme dependence of the measured top quark mass value. talk given by A. H. Hoang at the LCWS07, May 2007, DESY, Hamburg, Germany † email: [email protected] ‡ email: [email protected] § email: [email protected] ¶ email: [email protected]