[SEMINARI] SEMINAR: Maarten Golterman

[German Rodrigo Garcia]

Duality violations and spectral sum rules

Maarten Golterman
San Francisco State U. and IFAE
Wednesday, 24 of May of 2006     15:00 PM
IFIC's Seminar

Abstract

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.