Theory seminar (11am): Jack Holguin : Revealing simple scaling laws in heavy ion jets with Energy Correlators

Thursday 31 Oct 2024, 11:00 → 12:00 Europe/Amsterdam

Colloquium Room

Recently, the first-ever measurements of energy correlators in Pb-Pb collisions were released by the CMS Collaboration, revealing significant modifications compared to proton-proton (p-p) baselines. However, interpreting these results is challenging due to selection bias introduced by energy loss, which complicates the understanding of parton/hadron dynamics in the coloured medium. To address this, we introduce a novel EEC cross-ratio that reduces the bias by an order of magnitude while preserving sensitivity to medium effects. Building on this result, and using the light-ray operator product expansion (OPE), we demonstrate that nuclear modifications in both p-A and A-A collisions are characterised by an enhanced twist-4 contribution. The OPE constrains the functional form of this enhancement, enabling a more accurate interpretation of nuclear effects, while mitigating potential biases from quark-gluon fraction changes or further energy loss. These insights pave the way for a more precise characterisation of nuclear matter modifications in jet substructure, motivating further investigation of higher-point energy correlators.

Revealing simple scaling laws in heavy ion jets.pdf