Jiří Chýla (Praha):

Does the choice of scales matter at the LHC?

Abstract:

For a number of interesting physical quantities measured at HERA and TEVATRON the ambiguities resulting from the freedom in the choice of the renormalization and factorization scales prevent us from drawing clear conclusions on the presence of signals of new physics, like the BFKL dynamics. One might hope that at much higher energies available at the LHC perturbative QCD predictions will be much more stable. In this talk I will argue that this is not always the case and that the problem of scale setting may hinder even such important and seemingly clean observables like the ttbar production cross section.

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