The Spin Dependence of Diffractive Processes and Implications for the Small $x$ Behaviour of $g_1$ and the Spin Content of the Nucleon

Abstract

We show that if the Lorentz transformation properties of diffraction are other than scalar, the $x\to 0$ behaviour of $g_1(x,Q^2)$ can grow. We compare with new data on $g_1^p$ from SMC, assess implications for sum rules and for future studies of sea polarisation.

Comments: 9 pages + 1 figure added as a postscript file which should be stripped off before latexing