Measurement of the groomed jet radius and momentum splitting fraction in pp and Pb$-$Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV

Understand

This article presents groomed jet substructure measurements in pp and Pb$-$Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV with the ALICE detector.

• The Soft Drop grooming algorithm provides access to the hard parton splittings inside a jet by removing soft wide-angle radiation.
• We report the groomed jet momentum splitting fraction, $z_{\rm g}$, and the (scaled) groomed jet radius, $\theta_{\rm g}$.
• Charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm with resolution parameters $R = 0.2$ and $R = 0.4$.