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"A chiral twist to the QCD Schroedinger functional"

Relatore: Dr Stefan Sint- Trinity College - Dublin

Sala Feynman
30 Settembre 2008 ore 15.30

QCD can be renormalised at low energies by using experimental results for the hadron spectrum to fix the bare coupling and quark masses. With no free parameters left, any other observable, such as alpha_s(m_Z), becomes a prediction of the theory. In principle, lattice QCD is well-suite for such a strategy, but the presence of large scale differences poses a problem. A controlled connection between widely different scales can be established by using finite volume renormalisation schemes based on the Schroedinger functional. I will explain the advantages of this approach as well as its shortcomings. The latter can be partially overcome by a modification of the standard set-up, which can be interpreted as a chiral rotation of the standard Schroedinger functional.