Speaker
Description
Energy loss of high-momentum partons is one of the key signatures of the quark-gluon plasma formed in heavy-ion collisions.
Through measurements of the nuclear modification factor $R_{\rm AA}$, where a strong suppression of high $p_{\text{T}}$ particle yields is observed, parton energy loss has been confirmed in Pb--Pb collisions at the LHC.
However, in small collision systems, like pp and p--Pb, energy loss has not yet been confirmed.
In this talk, a measurement of the $R_{\rm AA}$ in OO and pO collisions at $\sqrt{s_{\rm NN}} = 5.36$ TeV and $\sqrt{s_{\rm NN}} = 9.62$ TeV, respectively, is presented. These results are based on the measured particle $p_{\text{T}}$ spectra of $\pi^0$ in OO, pO, and pp collisions using the ALICE Electromagnetic Calorimeter.
The measurement of the $R_{\rm pO}$ allows precise constraints on cold-nuclear matter effects. In combination with the $R_{\rm OO}$, this allows for a separation of cold and hot nuclear matter contributions and enables a quantitative determination of partonic energy loss in OO collisions.
The measurements are compared to theoretical model calculations that include both cold and hot nuclear matter effects.
| Is this an experimental talk? | Yes |
|---|---|
| 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 |