Selected recent HERMES results

The first phase of HERMES data taking covers the years 1995 to 2000. Data were taken with longitudinally polarised atomic 3 He (1995), hydrogen (1996-1997) and deuterium (1998--2000) gas targets, but also with several other unpolarised targets (H-2, D-2, He-3, He-4, N-2, Ne and Kr). Some selected results from this data taking period are discussed: the spin-dependent structure function g(1) (x, Q(2)) from deuterium, which has been measured in inclusive polarised deep-inelastic scattering with high accuracy down to x = 0.0021; quark and antiquark helicity distributions from semi-inclusive deep-inelastic scattering on hydrogen and deuterium. The data indicate that within the experimental accuracy the antiquark helicity distributions are consistent with zero and with each other and do riot favour a flavour asymmetry in the light quark sea or a substantial negative polarisation of the strange sea; an estimate of the gluon polarisation from the double-spin asymmetry in the production of pairs of high-p(T) hadrons; the measurement of single-spin azimuthal asymmetries in Deeply Virtual Compton Scattering which give access to combinations of Generalized Parton Distributions and via their moments to the contribution of orbital angular momenta of quarks to the spin of the nucleon; the first measurement of the tensor asymmetry AT and the tenser structure function b(1) (x) with a tensor polarized deuterium target; the first measurement of the Q(2) dependence of nuclear transparency in exclusive p(0) production from N-14 and the first measurement of nuclear hadron attenuation of identified fast charged and neutral pions, charged kaons, protons ant antiprotons produced from nitrogen and krypton targets.