Nucleon structure functions with domain wall fermions

Abstract

We present a quenched lattice QCD calculation of the first few moments of the\npolarized and un-polarized structure functions of the nucleon. Our calculations\nare done using domain wall fermions and the DBW2 gauge action with inverse\nlattice spacing ~1.3GeV, physical volume approximatelly (2.4 fm)^3, and light\nquark masses down to about 1/4 the strange quark mass. Values of the individual\nmoments are found to be significantly larger than experiment, as in past\nlattice calculations, but interestingly the chiral symmetry of domain wall\nfermions allows for a precise determination of the ratio of the flavor\nnon-singlet momentum fraction to the helicity distribution, which is in very\ngood agreement with experiment. We discuss the implications of this result.\nNext, we show that the chiral symmetry of domain wall fermions is useful in\neliminating mixing of power divergent lower dimensional operators with twist-3\noperators. Finally, we find the isovector tensor charge at renormalization\nscale 2 GeV in the MS bar scheme to be 1.192(30), where the error is the\nstatistical error only.\n