Jet Radius and Momentum Splitting Fraction with Dynamical Grooming in Heavy-Ion Collisions

We investigate the medium modifications of momentum splitting fraction and groomed jet radius with both dynamical grooming and soft drop algorithms in heavy-ion collisions. In the calculation, the partonic spectrum of initial hard scattering in p+p collisions is provided by the event generator PYTHIA8, and the energy loss of fast parton traversing in a hot/dense quantum-chromodynamic medium is simulated with the linear Boltzmann transport model. We predict the normalized distributions of the groomed jet radius θ_g and momentum splitting fraction z_g with the dynamical grooming algorithm in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV, then compare these quantities in dynamical grooming at a = 0.1, with that in soft drop at z_cut = 0.1 and β = 0. It is found that the normalized distribution ratios Pb+Pb/p+p with respect to z_g in z_cut = 0.1, β = 0 soft drop case are close to unity, those in a = 0.1 dynamical grooming case show enhancement at small z_g, and Pb+Pb/p+p with respect to θ_g in the dynamical grooming case demonstrate weaker modification than those in the soft drop counterparts. We further calculate the groomed jet number averaged momentum splitting fraction 〈z_g〉_jets and averaged groomed jet radius 〈θ_g〉_jets in p+p and A+A for both grooming cases in three $p_{\mathrm{T}}^{\mathrm{ch}\mathrm{jet}}$ intervals, and find that the originally generated well balanced groomed jets will become more momentum imbalanced and jet size less narrowed due to jet quenching, and weaker medium modification of z_g and θ_g in the a = 0.1 dynamical grooming case than in the soft drop counterparts.