Structure of the Pion from Full Lattice QCD

Abstract

Moments of generalised parton distributions can be related to off-forward matrix elements of local operators. We calculate a few of the leading twist matrix elements for the pion on the lattice. The simulations are performed using two flavours of dynamical fermions and a range of pion masses from 550 to 1090 MeV. Our lattice spacings and spatial volumes lie in the range 0.07-0.12 fm and (1.6-2.2 fm)^3, respectively. Key features of our investigation are the use of O(a) improved Wilson fermions and non-perturbative renormalisation. We present first results for the two lowest moments of the generalised parton distributions of the pion and compare the pion electromagnetic form factor F_pi to experimental data. Good agreement is found between lattice data and experiment.

6 pages, 3 figures, talk presented at Lattice 2005 (weak matrix elements)