Studies of the transverse spin-dependent structure functiong2(x, Q2)

We study the transverse spin-dependent nucleon structure function $g_2(x, Q^2)$ in leading order at large $Q^2$. After reviewing the operator-product-expansion analysis of $g_2(x, Q^2)$ we calculate the twist-3 contributions which arise from quark-gluon interactions and quark masses in the bag model. The result confirms the presence of significant twist-3 effects in $g_2(x, Q^2)$. We discuss two questions raised by our analysis: the validity of the Burkhardt-Cottingham sum rule and the relation to previous calculations of $g_2(x, Q^2)$ in versions of the parton model.