The Spin Structure Function g2.

We have measured the spin structure functions g[sub 2][sup p] and g[sub 2][sup d] over the kinematic range 0.02 ≤ x ≤ 0.8 and 0.7 ≤ Q2 ≤ 20 GeV2 by scattering 29.1 and 32.3 GeV longitudinally polarized electrons from transversely polarized NH3 and 6LiD targets. Our measured g2 approximately follows the twist-2 Wandzura-Wilczek calculation. The twist-3 reduced matrix elements d[sub 2][sup p] and d[sub 2][sup n] are less than two standard deviations from zero. The data are inconsistent with the Burkhardt-Cottingham sum rule. The Efremov-Leader-Teryaev integral is consistent with zero within our measured kinematic range. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]