Ma, W.Lu, D.Thomas, A.Li, Z.2006-07-052006-07-051998Nuclear Physics A, 1998; 635(4):497-5080375-94741873-1554http://hdl.handle.net/2440/10859We test the Gerasimov-Drell-Hearn (GDH) sum rule numerically by calculating the total photon absorption cross sections σ<inf>1/2</inf> and σ<inf>3/2</inf> on the nucleon via photon excitation of baryon resonances in the constituent quark model. A total of seventeen, low-lying, non-strange baryon resonances are included in this calculation. The transverse and longitudinal interference cross section, σ^TL<inf>1/2</inf>, is found to play an important role in the study of the Q² variation of the sum rule. The results show that the GDH sum rule is saturated by these resonances at a confidence level of 94%. In particular, the P<inf>33</inf>(1232) dominates at small Q². The GDH integral has a strong Q²-dependence below Q² = 1.0 GeV² and changes its sign around Q² = 0.3 GeV². It becomes weakly Q²-dependent for Q² > 1.0 GeV² because of the quick decline of the resonance contributions. © 1998 Published by Elsevier Science B.V.enJournal article0030004486001998206510.1016/S0375-9474(98)00202-40000745201000062-s2.0-003249647468492Thomas, A. [0000-0003-0026-499X]