We investigate finite size effects of the pion matrix element of the non-singlet, twist-2 operator corresponding to the average momentum of non-singlet quark densities. Using the quenched approximation, they come out to be surprisingly large when compared to the finite size effects of the pion mass. As a consequence, simulations of corresponding nucleon matrix elements could be affected by finite size effects even stronger which could lead to serious systematic uncertainties in their evaluation.
@article{arxiv.hep-lat/0403009,
title = {Finite size effects of a pion matrix element},
author = {M. Guagnelli and K. Jansen and F. Palombi and R. Petronzio and A. Shindler and I. Wetzorke},
journal= {arXiv preprint arXiv:hep-lat/0403009},
year = {2007}
}
Comments
12 pages, 5 figures; v2: version accepted for publication in Physics Letters B, minor changes, references updated