About
Jets are generated in heavy-ion collisions, and their interactions with the Quark-Gluon Plasma (QGP) produced in such collisions provide unique probes of QGP properties. Experimentally observable consequences of jet-QGP interactions include jet energy loss, modification of intra-jet structure, and jet angular deflection. Jet deflection can occur via multiple soft scatterings or single-hard Moliere scatterings off QGP constituents, and its observation will probe the nature of QGP quasi-particles. Such effects are expected to be most prominent at low jet transverse momentum ($p_\mathrm{T}$), which is where jet measurements are also sensitive to wake effects due to response of the QGP itself to the jet-medium energy transfer. Measurements that are differential in jet $p_\mathrm{T}$, jet radius $R$, and acoplanarity (deflection angle) may be able to disentangle these various mechanisms.
This talk presents new measurements of the semi-inclusive distribution of charged-particle jets recoiling from a trigger hadron in pp and central Pb--Pb collisions at $\sqrt{s_\mathrm{NN}}=5.02$ GeV. The measurement is performed using a background-subtraction technique which provides a precise data-driven subtraction of the large uncorrelated background contaminating the measurement, uniquely enabling the measurement of jet production and acoplanarity over a wide phase space, including the low jet $p_\mathrm{T}$ region for large $R$. This measurement in pp collisions provides a test of pQCD predictions for this process. We observe a striking medium-induced enhancement in recoil jet yield at low $p_\mathrm{T,jet}$, whose R-dependence enables a clear discrimination of in-medium jet scattering and QGP wake effects. The in-medium suppression of recoil yield at higher $p_\mathrm{T,jet}$ provides new insight into the mechanisms underlying jet quenching. Comparison to model calculations and their dependence on jet $R$ will be shown to interpret the results.
Refreshments will be served at…
The talk
Credits and licence
- Institution
- CERN
- Department
- LHC Seminar
- Speaker
- Jaime Norman
- Year
- 2023
- Language
- English
- Subjects
- Earth and environment
- Source
- CERN
- Licence
- CERN, as CERN states it. CERN's terms
- Attribution
- © CERN. CERN provides its audiovisual media free of charge for educational and informational use, credited to CERN; this lecture is shown in CERN's own player.
- Who can watch
- CERN gives no rating. Invisible Network shows it to Tweens profiles and older, judged from what the source says about it. How courses are placed