Jun 13 – 17, 2011
Europe/Berlin timezone
Proceedings are now available online at <a href="http://www.slac.stanford.edu/econf/C110613/">eConf</a>

Precision calculation of the pion electromagnetic form factor from lattice QCD

Jun 14, 2011, 4:50 PM
Festsaal (Künstlerhaus)



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Mr Bastian Brandt (Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, Mainz)


We present a lattice calculation of the vector form factor of the pion for two flavours of non-perturbatively O(a) improved Wilson fermions. For the measurements we utilise the CLS ensembles which include various lattice spacings and pion masses down to roughly 250 MeV. To obtain a fine momentum resolution near zero momentum transfer (q^2) twisted boundary conditions are employed using several properly tuned twist angles. In order to keep statistical fluctuations small we use stochastic wall sources for the computation of the propagators. Due to the fine resolution around q^2=0 we are able to determine the slope of the form factor and, in turn, extract the charge radius of the pion without any model dependence. Thereby, systematic effects for the latter are significantly reduced. The results for the form factor and the charge radius are then compared to chiral perturbation theory and other models which are then used to extrapolate the results to the physical point.

Primary author

Mr Bastian Brandt (Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, Mainz)


Dr Andreas Juettner (CERN, Physics Department, TH Unit) Prof. Hartmut Wittig (Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, Mainz)

Presentation materials