Search for the Jet-Induced Diffusion Wake in the Quark-Gluon Plasma Via Measurements of Jet-Track Correlations in Photon-Jet Events in (Formula Presented) Collisions at (Formula Presented) With the Atlas Detector

Abstract

This paper presents a measurement of jet-track correlations in photon-jet events, using 1.72 (Formula presented) of (Formula presented) data at (Formula presented) recorded with the ATLAS detector at the LHC. Events with energetic photon-jet pairs are selected, where the photon and jet are approximately back-to-back in azimuth. The angular correlation between jets and charged-particle tracks with transverse momentum ((Formula presented)) in the range 0.5-2.0 GeV in the hemisphere opposite to the jet, (Formula presented), is measured as a function of their relative pseudorapidity difference, (Formula presented). In central (Formula presented) collisions, these correlations are predicted to be sensitive to the diffusion wake in the quark-gluon plasma resulting from the lost energy of high-(Formula presented) partons traversing the plasma, with a characteristic modification as a function of (Formula presented). The correlations are examined with different selections on the jet-to-photon (Formula presented) ratio to select events with different degrees of energy loss. No diffusion wake signal is observed within the current sensitivity and upper limits at 95% confidence level on the diffusion wake amplitude are reported. ©2025 CERN, for the ATLAS Collaboration.