Speaker
Description
Jet substructure measurements in heavy-ion (HI) collisions constrain the microscopic interaction mechanisms between energetic partons and the quark–gluon plasma. Jet-quenching models predict modifications of the jet-hadrochemical composition in heavy-ion collisions due to jet-medium interactions, allowing measurements of identified particles in jets to help discriminate between different proposed jet-medium interaction mechanisms. Furthermore, models with a jet wake, imprinted on the medium by the traversing jet, predict enhanced soft-particle production at large angles from the jet axis. As such, jet-hadrochemistry studies can also probe the thermalisation properties of the QCD medium.
We present the first measurements with ALICE of $\pi$, K, and p ratios within charged-particle-jets and the underlying event as a function of particle transverse momentum in pp and Pb--Pb collisions, providing the first hints of jet-hadrochemistry modifications in HI collisions. We also report a new study using the high-statistics data sample of Run 3, which measures the jet radial dependence of the particle composition in Pb--Pb collisions for the first time. This differential measurement probes the transition from the hard jet core to its soft periphery, yielding key insights into medium response and QCD thermalisation in the jet wake. These measurements leverage the excellent PID capabilities of ALICE over a wide momentum range. We compare the results with theoretical models to probe the relative effects of modified jet fragmentation and medium response.
| Is this an experimental talk? | Yes |
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| Is this on behalf of a collaboration? | Yes |
| Which collaboration? | ALICE |
| Are you willing to present as a poster if it is not selected for oral presentation? | Yes |