Constraining the color-charge effects of energy loss with jet axis-based substructure studies in PbPb collisions at 5.02 TeV

This study investigates the jet axis decorrelation in inclusive jets using lead-lead (PbPb) collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The decorrelation is defined as the angular difference between two jet axis definitions, obtained by applying different recombination schemes to the constituents of jets reconstructed with the anti- k T sequential algorithm and a distance parameter of R = 0.4. The analysis is based on a data set collected with the CMS detector at the CERN LHC in 2018, corresponding to an integrated luminosity of 0.66 nb −1 . The decorrelation distributions are measured as a function of collision centrality and jet transverse momentum. A centralitydependent trend is observed, with the distributions progressively narrowing in more central events. This narrowing may result from medium-induced modifications of the jet substructure or reflect color charge effects in jet energy loss. This measurement explores previously unexplored kinematic regions, providing valuable insights into the color charge dependence of energy loss and jet quenching models.