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

We present the first theoretical study on heavy-flavor jet angularities (\lambda^\kappa_\alpha) in Pb+Pb collisions at \sqrts_\rm NN=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 D^0-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 D^0-tagged jets in Pb+Pb collisions relative to that in p+p collisions for a jet transverse momentum of 10 < p_\rm T, jet^\rm ch < 20 GeV/c. In contrast, the angularity distributions of the inclusive and D^0-tagged jets become narrower in Pb+Pb collisions relative to p+p at p_\rm T, jet^\rm ch > 20 GeV/c because of the strong influence of selection bias. Additionally, by comparing the average angularities \langle \lambda^\kappa_\alpha \rangle of the inclusive, D^0-tagged, and B^0-tagged jets with varying \alpha and \kappa, we show that the larger the quark mass, the lower the jet's \langle \lambda^\kappa_\alpha \rangle values are. As a result of the slenderer initial distribution, we predict that compared with inclusive jets, heavy-flavor jets, especially B^0-tagged ones, will suffer stronger modifications of \langle \lambda^\kappa_\alpha \rangle in Pb+Pb relative to p+p at 10 < p_\rm T, jet^\rm ch < 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.