Inclusive diffraction in eA at small x with the Sartre event generator

Abstract

We present an extension of the Sar\emph{t}re event generator that implements inclusive diffractive deep inelastic scattering for both proton and nuclear targets at small $x$. The calculation is performed in the colour-dipole picture using the IPsat and IPnonsat dipole amplitudes that Sar\emph{t}re also employs for exclusive processes, and includes the transverse and longitudinal $q\bar q$ contributions together with the $q\bar qg$ Fock state that dominates at large $M_X$. The partonic diffractive system is hadronised with \pythia, giving fully exclusive hadronic final states. We compare to the combined H1 and ZEUS inclusive diffractive measurements and to diffractive $D^*$ production, and present predictions for the Electron-Ion Collider. This makes Sar\emph{t}re the only event generator providing inclusive diffractive DIS in small-$x$ for both $ep$ and $eA$ collisions.