Evaluation of Jet Substructure Observables for sPHENIX*

The sPHENIX collaboration at RHIC aims to understand the quark-gluon plasma (QGP) that emerges during heavy ion collisions. Jets, cones of final state particles produced by parton hadronization, are effective probes of the QGP. Jet quenching refers to the observed energy differences between jets resulting from proton-proton (pp) collisions and those resulting from heavy ion collisions. Embedding simulated pp collisions in a heavy ion background suggests that quenching is likely due to the traversal of jets through the QGP, rather than multiplicity effects.

This analysis focuses on jet substructure by analyzing subjets,  jets of smaller cone size contained within jets of larger cone size. Specifically, we examine the momentum fraction and opening angle of each event’s leading larger jet. Using simulated collision data from the sPHENIX Mock Data Challenge 2 along with background subtraction methods, these observables are calculated for truth pp collision data and reconstructed sPHENIX calorimeter data. The calculated observables are compared across data sets to assess whether those for the sPHENIX data set accurately reflect the true structure of the jets and can thus be analyzed by sPHENIX.