Speaker
Description
The jet-radius dependence of the nuclear modification factor $R_{AA}$ probes how energy lost by partons in the quark-gluon plasma is redistributed in angle. Its interpretation, however, is entangled with the steeply falling jet spectrum and selection biases. This poster presents a comparative, data-driven study of radius-differential jet quenching in central (0-10%) Pb+Pb collisions at $\sqrt{s_{NN}}=5.02~\mathrm{TeV}$. We analyze published ATLAS measurements for inclusive, photon-tagged, and dijet selections, together with ALICE charged-jet results using two complementary observables: the $R_{AA}$ double ratio $R_{AA}^{R/0.2}\equiv R_{AA}(R)/R_{AA}(0.2)$ and the fractional energy loss $S_{\mathrm{loss}}$. We observe strong selection- and measurement-dependent differences: ATLAS dijet double ratios exceed unity at larger $R$, while ALICE charged-jet double ratios are below unity. By exploiting $S_{\mathrm{loss}}$ to mitigate spectral bias, we observe an ordering of the extracted energy loss across selections in the kinematic range studied, with sub-leading dijets exhibiting the largest shifts and $\gamma$-tagged jets the smallest. These results underscore the competing roles of out-of-cone energy transport and selection bias, and provide radius-resolved, data-driven constraints for models of jet quenching.
| Is this an experimental talk? | Yes |
|---|---|
| Is this on behalf of a collaboration? | No |
| Are you willing to present as a poster if it is not selected for oral presentation? | Yes |