Pion electromagnetic form factor from full lattice QCD
Abstract
We present preliminary results from the first calculation of the pion electromagnetic form factor at physical light quark masses. This form factor parameterises the deviations from the behaviour of a point-like particle when a photon hits the pion. These deviations result from the internal structure of the pion and can thus be calculated in QCD. We use three sets (different lattice spacings) of n_f=2+1+1 lattice configurations generated by the MILC collaboration. The Highly Improved Staggered Quark formalism (HISQ) is used for all of the sea and valence quarks. Using lattice configurations with u/d quark masses very close to the physical value is an advantage, as we avoid the chiral extrapolation. We study the shape of the vector (f_+) form factor in the q^2 range from 0 to -0.12 GeV^2 and extract the mean square radius, <r^2_v>. The shape of the vector form factor and the resulting radius is compared with experiment.
Keywords
Cite
@article{arxiv.1311.3513,
title = {Pion electromagnetic form factor from full lattice QCD},
author = {Jonna Koponen and Francis Bursa and Christine Davies and Gordon Donald and Rachel Dowdall},
journal= {arXiv preprint arXiv:1311.3513},
year = {2013}
}
Comments
Presented at the 31st International Symposium on Lattice Field Theory (Lattice 2013), 29 July - 3 August 2013, Mainz, Germany