Speaker
Description
Perturbative QCD calculations indicate that asymptotically free heavy quarks are less likely than lighter flavors to emit gluonic radiation at small angles, a phenomenon called the Dead Cone Effect (DCE). $D^0$-tagged jets at RHIC collider energies offer a near ideal regime to probe this effect, due to the kinematic suppression of gluon jets energetic enough to produce charm pairs--which are likely to be misreconstructed with net charm. Measurements of DCE at the LHC must contend with this challenging "charm-subjet" contribution in abundance, making a low-energy RHIC measurement essential to gain clear perspective on the mass dependence of gluonic radiation in QCD.
This poster presents the early stages of a DCE measurement at STAR using Energy-Energy Correlators (EECs), including simulation studies with PYTHIA and $D^0$-tagged jet reconstruction in $pp$ collisions at $\sqrt{s}=200$ GeV. EECs, energy-weighted angular correlations between hadrons in a jet, are infrared/collinear (IRC)-safe observables shown to be sensitive to DCE.$^1$ The persistence of EEC signals across the IRC divergences of QCD enable the direct comparison of EEC measurements to theoretical pQCD predictions. Through feasibility studies and initial results, we see compelling promise of this EEC measurement to reveal the Dead Cone at RHIC.
[1] E. Craft, K. Lee, B. Meçaj, and I. Moult, Beautiful and Charming Energy Correlators, (2022), arXiv:2210.09311 [hep-ph].
| Is this an experimental talk? | Yes |
|---|---|
| Is this on behalf of a collaboration? | Yes |
| Which collaboration? | STAR |
| Are you willing to present as a poster if it is not selected for oral presentation? | Yes |