function data,” Phys. Lett. B 665 , 349 (2008) [ arXiv:0803.4119 [hep-ph]]. [40] S. D. Drell and A. C. Hearn, “Exact Sum Rule for Nucleon Magnetic Moments,” Phys. Rev. Lett. 16 , 908 (1966); S. B. Gerasimov, “A sum rule for magnetic moments and the damping of the nucleon magnetic moment in nuclei,” Sov. J. Nucl. Phys. 2 (1966) 430 [Yad. Fiz. 2 (1966) 598]. [41] See, for example, H. Gao and L. Zhu, “Pion photoproduction on the nucleon,” AIP Conf. Proc. 747 , 179 (2005) [ arXiv:nucl-ex/0411014 ], and references therein. [42] See, for example, J. P. Chen, A. Deur and Z. E. Meziani, “Sum rules and moments of the nu- cleon spin structure functions,” Mod. Phys. Lett. A 20 (2005) 2745 [ arXiv:nucl-ex/0509007 ], and references therein. [43] Upcoming JLab data: JLab experiments E97-110, J-P Chen, A. Deur, F. Garibaldi spokesper- sons; EG1b, V. Burkert, D. Crabb, M. Tauiti, G. Dodge and S. Khun spokespersons; EG4, M. Battaglieri, A. Deur, R. DeVita, G. Dodge, M. Ripani and K. Slifer spokespersons. [44] J. C. R. Bloch, “Multiplicative renormalizability and quark propagator,” Phys. Rev. D 66 , 034032 (2002) [ arXiv:hep-ph/0202073 ]; P. Maris and P. C. Tandy, “Bethe-Salpeter study of vector meson masses and decay constants,” Phys. Rev. C 60 , 055214 (1999) [ arXiv:nucl-th/9905056 ]; C. S. Fischer and R. Alkofer, “Infrared exponents and running cou- pling of SU(N) Yang-Mills theories,” Phys. Lett. B 536 , 177 (2002) [ arXiv:hep-ph/0202202 ]; C. S. Fischer, R. Alkofer and H. Reinhardt, “The elusiveness of infrared critical exponents in Landau gauge Yang-Mills theories,” Phys. Rev. D 65 , 094008 (2002) [ rXiv:hep-ph/0202195 ]; R. Alkofer, C. S. Fischer and L. von Smekal, “The infrared behaviour of the running coupling in Landau gauge QCD,” Acta Phys. Slov. 52 , 191 (2002) [ arXiv:hep-ph/0205125 ]; M. S. Bhag- wat, M. A. Pichowsky, C. D. Roberts and P. C. Tandy, “Analysis of a quenched lattice-QCD dressed-quark propagator,” Phys. Rev. C 68 , 015203 (2003) [ arXiv:nucl-th/0304003 ]. [45] V. D. Burkert and B. L. Ioffe, “On the Q 2 variation of spin dependent deep inelastic electron - proton scattering,” Phys. Lett. B 296 , 223 (1992); “Polarized Structure Functions of Proton and Neutron and The Gerasimov-Drell-Hearn and Bjorken Sum Rules,” J. Exp. Theor. Phys. 78 , 619 (1994) [Zh. Eksp. Teor. Fiz. 105 , 1153 (1994)]. [46] G. Parisi, “Conformal invariance in perturbation theory,” Phys. Lett. B 39 , 643 (1972). [47] M. Gell-Mann and F. E. Low, “Quantum electrodynamics at small distances,” Phys. Rev. 95 , 1300 (1954). 29