Eur. Phys. J. A (2003) 18: 503-505
https://doi.org/10.1140/epja/i2002-10270-x

Moments of polarized parton distribution functions

¹ U. L. Pasteur, LPT, Strasbourg, France
² Theoretische Physik T39, Physik Department, TU München, Garching, Germany
³ FZ Jülich, IKP(Th), Jülich, Germany

^* e-mail: themmert@physik.tu-muenchen.de

Abstract

We present novel results for the first moment of the spin-dependent structure function g ₁(x,Q ²) of the nucleon at “small” (Q ² < 0.3 GeV²) photon virtuality in the framework of a relativistic formulation of baryon chiral perturbation theory. We perform a next-to-leading order calculation and obtain significant differences to previously found results based on the heavy-baryon approach for the proton and neutron.