Eur. Phys. J. A 24, s1.23-s1.28 (2005)
DOI: 10.1140/epjad/s2005-05-004-0

Spin structure of the nucleon

Pasquale Di Nezza

Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Frascati, via E. Fermi 40, I-00044 Frascati, Rome, Italy

Pasquale.DiNezza@lnf.infn.it

(Received 24 September 2004 / Published online 08 February 2005)

Abstract

HERMES is a second generation experiment to study the spin structure of the nucleon, in which measurements of the spin dependent properties of semi-inclusive deep-inelastic lepton scattering are emphasized. The first experimental results from measurements of single-spin asymmetries for pions and kaons in deep-inelastic scattering with transverse target polarization are discussed. Longitudinally polarized beam and target data provide information on the flavor decomposition of the polarized quark distributions in the nucleon and a first glimpse of the gluon polarization. Moreover, first preliminary results for the unpolarized e p-> e n π⁺   total cross section are presented and compared to Generalized Parton Distribution calculations.

PACS: 13.87.Fh - 13.60.-r - 13.88.+e

© Società Italiana di Fisica, Springer-Verlag 2005