Abstract
The virtual photon absorption cross section differences [alpha(1/2) - alpha(3/2)] for the proton and neutron have been determined from measurements of polarised cross section asymmetries in deep inelastic scattering of 27.5 GeV longitudinally polarised positrons from polarised H-1 and He-3 internal gas targets. The data were collected in the region above the nucleon resonances in the kinematic range v < 23.5 GeV and 0.8 GeV2 < Q(2) < 12 GeV2. For the proton the contribution to the generalised Gerasimov-Drell-Hearn integral was found to be substantial and must be included for an accurate determination of the full integral. Furthermore the data are consistent with a QCD next-to-leading order fit based on previous deep inelastic scattering data. Therefore higher twist effects do not appear significant. (C) 1998 Elsevier Science B.V. All rights reserved.
Original language | English |
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Pages (from-to) | 531-538 |
Number of pages | 8 |
Journal | Physics Letters B |
Volume | 444 |
Issue number | 3-4 |
DOIs | |
Publication status | Published - 24 Dec 1998 |
Externally published | Yes |
Keywords
- SPIN STRUCTURE-FUNCTION
- STRUCTURE-FUNCTION G(1)(N)
- RESONANCE REGION
- POLARIZED HE-3
- PARTON MODEL
- SUM-RULES
- E-P
- SCATTERING
- NUCLEON