ar X iv : n uc l - th / 9 90 50 04 v 1 4 M ay 1 99 9 Q 2 - Dependence of the Drell - Hearn - Gerasimov integral

ar X iv : h ep - p h / 99 05 33 4 v 1 1 3 M ay 1 99 9 Drell - Hearn - Gerasimov Sum Rule for the Nucleon in the Large - N c Limit

We show that the Drell-Hearn-Gerasimov sum rule for the nucleon is entirely saturated by the ∆ resonance in the limit of a large number of colors, Nc → ∞. Corrections are at relative order 1/N2 c . Typeset using REVTEX

ar X iv : h ep - p h / 04 11 19 1 v 1 1 5 N ov 2 00 4 POLARIZED STRUCTURE FUNCTIONS AND THE GDH INTEGRAL FROM LATTICE QCD

The Gerasimov-Drell-Hearn integral I GDH (Q 2), and its relation to polarized nu-cleon structure functions, is discussed from the lattice perspective. Of particular interest is the variation of I GDH (Q 2) with Q 2 , and what it may teach us about the origin and magnitude of higher-twist contributions.

ar X iv : n uc l - th / 9 90 50 49 v 1 2 1 M ay 1 99 9 η - and η ′ - meson production in the reaction pn → dM near threshold

ar X iv : n uc l - th / 9 90 50 49 v 2 2 6 M ay 1 99 9 η - and η ′ - meson production in the reaction pn → dM near threshold

- th / 9 71 20 36 v 1 1 0 D ec 1 99 7 Q 2 – Dependence of the Gerasimov - Drell - Hearn Sum Rule

We test the Gerasimov-Drell-Hearn (GDH) sum rule numerically by calculating the total photon absorption cross sections σ1/2 and σ3/2 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, σTL 1/2, is found...