I will describe our ongoing work on implementing inclusive diffraction in the Sartre event generator at small x. Sartre is using the colour dipole model (both with and without saturation effects). For inclusive diffraction we need to take two Fock states of the interacting dipole into consideration: the quark-antiquark dipole, and the quark-antiquark-gluon double dipole. The latter is relevant for the limit of small values of beta or large values of Q2, both resulting in a large invariant mass in the diffractive final state. As these cross section calculations are somewhat CPU intense, I will discuss a method of using cross section lookup tables for fast event generation. Currently, we are only considering coherent diffraction, but these methods can be extended to also include incoherent diffraction if needed in the future.
For generating a final state, the resulting quark-antiquark, or quark-antiquark-gluon states are fed into Pythia 8 for string fragmentation resulting in a hadronic final state in the event record. Furthermore, we have devised a semiclassical multiple scattering model to take into account azimuthal decorrelations between the final state particles, which could be used as a signal for a saturated state of matter.
