Details

Autor(en) / Beteiligte

• Airapetian, A.
• Akopov, N.
• Akushevich, I.
• Amarian, M.
• Arrington, J.
• De Schepper, D.
• Jackson, H. E.
• Makins, N. C. R.
• O'Neill, T. G.
• Potterveld, D. H.
• HERMES Collaboration
• Physics
• Yerevan Physics Inst
• DESY Zeuthen
• National Inst. voor Kernfysica en Hoge-Energiefysica
• Inst. Superiore di Sanita
• Massachusetts Inst. of Tech
• Univ. of Illinois

Titel

The Q{sup 2}-dependence of the generalised Gerasimov-Drell-Hearn integral for the proton

Ist Teil von

• Physics letters. B, 2000-11, Vol.494 (1-2 ; Nov. 23, 2000)

Ort / Verlag

United States

Erscheinungsjahr

2000

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• The dependence on Q{sup 2} (the negative square of the 4-momentum of the exchanged virtual photon) of the generalised Gerasimov-Drell-Hearn integral for the proton has been measured in the range 1.2 GeV{sup 2}<Q{sup 2}<12 GeV{sup 2} by scattering longitudinally polarised positrons on a longitudinally polarised hydrogen gas target. The contributions of the nucleon-resonance and deep inelastic regions to this integral have been evaluated separately. The latter has been found to dominate for Q{sup 2}>3 GeV{sup 2}, while both contributions are important at low Q{sup 2}. The total integral shows no significant deviation from a 1/Q{sup 2} behavior in the measured Q{sup 2} range, and thus no sign of large effects due to either nucleon-resonance excitations or nonleading twist.