Medium Modifications of Heavy-Flavor Jet Angularities in High-Energy Nuclear Collisions

We present the first theoretical study on heavy-flavor jet angularities (λ^κ_α) in Pb+Pb collisions at √SNN = 5.02 TeV. The initial production of heavy-flavor jets was carried out using the POWHEG+PYTHIA8 prescription. In contrast, the SHELL transport model describes jet evolution in the quark-gluon plasma (QGP). In p+p collisions, we observed narrower angularity distributions for D⁰-tagged jets than for inclusive jets, consistent with the ALICE preliminary results. We then demonstrate that jet quenching in the QGP slightly widens the angularity distribution of D⁰-tagged jets in Pb+Pb collisions relative to that in p+p collisions for a jet transverse momentum of 10 < p_\mathrmT, \text jet ^\mathrmch < 20 GeV/c. In contrast, the angularity distributions of the inclusive and D⁰-tagged jets become narrower in Pb+Pb collisions relative to p+p at p_\mathrmT, \text jet ^\mathrmch > 20 GeV/c because of the strong influence of selection bias. Additionally, by comparing the average angularities (λ^κ_α) of the inclusive, D⁰-tagged, and B⁰-tagged jets with varying α and κ, we show that the larger the quark mass, the lower the jet’s (λ^κ_α) values are. As a result of the slenderer initial distribution, we predict that compared with inclusive jets, heavy-flavor jets, especially B⁰-tagged ones, will suffer stronger modifications of (λ^κ_α) in Pb+Pb relative to p+p at 10 < p_\mathrmT, \text jet ^\mathrmch < 20 GeV/c. For a larger jet radius, a more significant broadening of the jet angularities was predicted because of the enhanced contribution of the wide-angle particles.