por
Maarten Golterman
(San Francisco State U. and IFAE)
→
Europe/Madrid
Sala Seminarios IFIC (Edf. Institutos de Investigación)
Sala Seminarios IFIC
Edf. Institutos de Investigación
Descripción
We have investigated the effects of quark-hadron duality violations in a simple model for the difference of the vector and axial-vector two-point functions. The advantage of using a model is that OPE coefficients and spectral moments can be exactly calculated, and thus compared. The model also applies to a finite number of colors. It gives a semi-realistic description of actual data, and we use this to get an idea of the size of the errors made with various approaches which have been used in practice with regard to duality violations. We find that in the model duality violations are large. We suggest a heuristic method for taking duality violations into account.