Elucidating QCD using charm-tagged jet substructure with ALICE

by Preeti Dhankher (University of California, BerkeleyUniversity of California, Berkeley)

Thursday 30 Nov 2023, 14:00 → 16:00 Europe/Warsaw

4402 (IFJ-PAN)

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 understood 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 direct 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 dependencies, 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 reconstructed 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 measurement 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 generalized 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.

HF_IFJ_Krakow_30Nov.pdf