Speaker
Description
Jet substructure provides precise tests of Quantum Chromodynamics (QCD) and offers more differential ways to study hadronization mechanisms, compared to measurements of single hadrons. QCD predicts that jet radiation patterns depend on the mass and color charge of the initiating parton. Parton showers, in particular, are sensitive to the different Casimir factors of quarks and gluons, as well as to the mass of partons through the dead-cone effect.
In this talk we present three key charm-tagged jet measurements, using jets tagged with a reconstructed $\rm{D^{0}}$-meson. The first are measurements of the differences between three different axis definitions inside the jets. These different definitions vary in their sensitivity to wide-angle soft radiation and systematically probe the radiation pattern off of charm quarks. Next are the jet angularities, which characterise the weighted angular distribution of the jet constituents. These powerful observables probe the parton shower, with sensitivity to mass and Casimir effects that can be tuned by adjusting the importance of wide-angle radiation. Finally, we present the first measurement of the energy-energy correlator for $\rm{D^{0}}$-meson tagged jets. This observable is defined as the energy-weighted cross section of particle pairs within jets and reveals the detailed structure of QCD radiation from heavy quarks, allowing for a distinction between perturbative and non-perturbative effects in charm showers. Comparisons of all these results to measurements of dominantly gluon-initiated jets, as well as to various event generators, are sensitive to flavor-dependent effects in both the parton shower and hadronization mechanisms. Moreover, comparisons with next-to-leading order calculations emphasize the need for improved theoretical modelling of heavy-quark jets and provide critical insights into the parton-to-hadron transition in QCD.
| Category | Experiment |
|---|---|
| Collaboration (if applicable) | ALICE |
