Jet radius and momentum splitting fraction with dynamical grooming in heavy-ion collisions

Abstract

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 PYTHIA 8, and the energy loss of fast parton traversing in a hot/dense QCD medium is simulated with the Linear Boltzmann Transport (LBT) model. We predict the normalized distributions of the groomed jet radius ${\theta }_g$ 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 $z_{\mathrm{cut}}=0.1$ and $\beta =0$. It is found that the normalized distribution ratios Pb+Pb/p+p with respect to $z_g$ in $z_{\mathrm{cut}}=0.1$, $\beta =0$ soft drop case are close to unity and those in $a=0.1$ dynamical grooming case show enhancement at small $z_g$, and Pb+Pb/p+p with respect to ${\theta }_g$ 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 $⟨{\mathrm{z}}_{\mathrm{g}}{⟩}_{\mathrm{jets}}$ and averaged groomed jet radius $⟨{\theta }_{\mathrm{g}}{⟩}_{\mathrm{jets}}$ 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 less jet size narrowing due to jet quenching, and weaker medium modification of $z_g$ and ${\theta }_g$ in $a=0.1$ dynamical grooming case than in the soft drop counterparts.

7 pages, 3 figures, 2 tables

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Cited by in corpus (5)

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• Isolating perturbative QCD splittings in heavy-ion collisions
• Phenomenological study of the angle between jet axes in heavy-ion collisions
• Hadron productions and jet substructures associated with $Z^0/\gamma$ in Pb+Pb collisions at the LHC
• The Fox-Wolfram Moment of Jet Production in Relativistic Heavy Ion Collisions