Spin Dependence of Deep Inelastic Diffraction

TL;DR

This paper derives a perturbative model for the polarized diffractive structure function in deep inelastic scattering, highlighting the significance of double logarithmic enhancements at small x and estimating the perturbative contribution to spin asymmetry.

Contribution

It introduces a perturbative approach to polarized diffractive structure functions, including double logarithmic resummation and transition to nonperturbative regimes.

Findings

Perturbative contribution to spin asymmetry exceeds nonperturbative estimates.

Double logarithmic terms significantly enhance the polarized diffractive amplitude at small x.

Resummation of these terms is outlined for high-energy limit.

Abstract

Using a perturbative model for diffractive interactions, we derive an expression for the polarized diffractive structure function $g_1^D$ in the high energy limit. This structure function is given by the interference of diffractive amplitudes with polarized and unpolarized exchanges. For the polarized exchange we consider both two-gluon and quark-antiquark amplitudes. The polarized diffractive amplitude receives sizable contributions from non-strongly ordered regions in phase space, resulting in a double logarithmic enhancement at small $x$. The resummation of these double logarithmic terms is outlined. We also discuss the transition from our perturbative expression to the nonperturbative region. A first numerical estimate indicates that the perturbative contribution to the spin asymmetry is substantially larger than the nonperturbative one.