Eur. Phys. J. A (2004) 19: 249-256
https://doi.org/10.1140/epjad/s2004-03-041-9

Laboratory physics programs and new facilities

Selected recent HERMES results

Physikalisches Institut, Universität Erlangen-Nürnberg, D-91058 Erlangen

Received: 19 August 2003
Published online: 12 February 2004

Abstract

The first phase of HERMES data taking covers the years 1995 to 2000. Data were taken with longitudinally polarised ³He (1995), hydrogen (1996-1997) and deuterium (1998-2000) targets, but also with several other unpolarised targets (H₂, D₂, ³He, ⁴He, N₂, Ne and Kr). Some selected results from this data taking period are discussed: the spin-dependent structure function g ₁ from deuterium, which has been measured with high accuracy down to x = 0.0021; quark and antiquark helicity distributions from semi-inclusive deep-inelastic scattering on hydrogen and deuterium, which indicate that the antiquark distributions are consistent with zero and with each other and do not favour a substantial negative polarisation of the strange quark sea; and the first measurement of nuclear attenuation of identified fast charged and neutral pions, charged kaons, protons and antiprotons produced from nitrogen and krypton targets.