Preeti Dhankher, University of California, Berkeley

"Elucidating QCD using charm-tagged jet substructure with ALICE"

Abstract: In high-energy hadronic collisions, heavy quarks (charm and beauty), due to their large masses (mq >> ΛQCD), are mostly produced in the hard QCD processes during the early stages of the collisions. Their production is well un- derstood by perturbative quantum chromodynamics (pQCD) calculations. Jets, which are collimated sprays of particles produced by the hard-scattered partons, have been a crucial observable in high-energy particle physics as they provide di- rect access to the kinematics of the parton initiating the shower. The properties of partonic fragmentation in QCD depend on the flavors of the partons involved in the 1→2 splitting processes that drive parton showers. These dependencies arise from the differences in the Casimir factors of quarks and gluons, as well as the mass of heavy quarks (dead-cone effect). To explore these flavor depen- dencies, we use heavy-flavor tagged jets as an experimental tool, particularly at low and intermediate transverse momenta where mass effects are significant.

In this talk, I will present the recent results on charm-tagged (fully re- constructed D0-mesons) jets by the ALICE experiment at the Large Hadron Collider (LHC). These results include the measurements of the fragmentation function of jets containing fully reconstructed D0-mesons, first direct measure- ment of the dead-cone effect at colliders, using the comparison of Lund planes of charm-tagged jets and inclusive jets, and the first measurement of jet gener- alized angularity which can be tuned in their sensitivity to mass and Casimir effects. Comparisons to flavor-untagged jet sample will probe both the flavor dependencies due to the mass of the charm quark, as well as the high purity quark nature of the D0-tagged jet sample. Further comparisons to different MC generators will access the role of these flavor dependencies in different parton shower prescriptions.