eHIJING event generator for jet tomograph in electron-ion collisions

In deep-inelastic scatterings (()DIS()), an incident electron transfer a large momentum change to a quark in the hadronic target by exchanging a highly-virtual photon. In nuclear (()(Z, A)()) DIS, the quark continues to interact with the rest of the target with an enhanced probability that is proportional (A^{1/3}), causing the transverse momentum distribution relative the virtual photon to broadening as compared to proton/deutron DIS.

One can use these final-state interactions to probe the transverse momentum distribution of small-(x) gluon and obtain a detailed understanding of the microscopic composition of nuclei. The precise amount of parton momentum broadening (\Delta \langle p_T^2\rangle) is also closely related to the gluon saturation behavior.

However, the effect of momentum broadening on observables is complicated by QCD radiations and hadronization, which are also modified by nuclear effects. To make this connection from nuclear structure to final-state observables, we are developing an event generator that takes into account multiple partonic collisions, medium-modified parton shower and hadronization. The resulting “electron-Heavy-Ion-Jet-INteraction-Generator” (()eHIJING()) will benefit the testing of theoretical assumptions of jet-medium interactions, experimental and observables design, and ultimately to the mapping of the inner structure of the nuclei.