Understand
One key difference in current energy loss models lies in the treatment of the Altarelli-Parisi, AP, splitting functions.
- It has been shown that the shared momentum fraction, henceforth called Jet Splitting Function $z_g$ as determined by the SoftDrop grooming process can be made a Sudakov-safe measurement of the symmetrized AP functions in p+p collisions.
- The STAR collaboration presents the first z_g measurements at $\sqrt{s_{NN}}=200$ GeV in p+p and Au+Au collisions, where in Au+Au we use the specific di-jet selection introduced in our previous momentum imbalance measurement.
- For a jet resolution parameter of $R=0.4$, these di-jet pairs were found to be significantly imbalanced with respect to p+p, yet regained balance when all soft constituents were included.