The Q-dependence of the generalised Gerasimov-Drell-Hearn integral for the deuteron, proton and neutron
| Autor: | Michel Vetterli, Fritz-Herbert Heinsius, Gunar Schnell, Naryshkin Iurii, Pasquale Di Nezza, Jeffrey Brack, Armine Rostomyan, Giuseppe Ciullo, Paul Reimer, Zaven Hakopov, Marco Statera, Frank Ellinghaus, Manuella Vincter, Gerard Van der Steenhoven, Michael Tytgat, Luigi Lagamba |
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| Rok vydání: | 2003 |
| Předmět: |
Physics
Particle physics Range (particle radiation) Physics and Astronomy (miscellaneous) Magnetic moment Proton 010308 nuclear & particles physics Nuclear Theory Deep inelastic scattering 01 natural sciences Deuterium 0103 physical sciences High Energy Physics::Experiment Neutron Sum rule in quantum mechanics Nuclear Experiment 010306 general physics Engineering (miscellaneous) |
| Zdroj: | The European Physical Journal C. 26:527-538 |
| ISSN: | 1434-6052 1434-6044 |
| DOI: | 10.1140/epjc/s2002-01118-x |
| Popis: | The Gerasimov-Drell-Hearn (GDH) sum rule connects the anomalous contribution to the magnetic moment of the target nucleus with an energy-weighted integral of the difference of the helicity-dependent photoabsorption cross sections. The data collected by HERMES with a deuterium target are presented together with a re-analysis of previous measurements on the proton. This provides a measurement of the generalised GDH integral covering simultaneously the nucleon-resonance and the deep inelastic scattering regions. The contribution of the nucleon-resonance region is seen to decrease rapidly with increasing $Q^2$. The DIS contribution is sizeable over the full measured range, even down to the lowest measured $Q^2$. As expected, at higher $Q^2$ the data are found to be in agreement with previous measurements of the first moment of $g_1$. From data on the deuteron and proton, the GDH integral for the neutron has been derived and the proton--neutron difference evaluated. This difference is found to satisfy the fundamental Bjorken sum rule at $Q^2 = 5$ GeV$^2$. |
| Databáze: | OpenAIRE |
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