Speaker
Description
Direct photons provide a unique probe of the quark–gluon plasma (QGP), as they are emitted throughout all stages of the collision and escape the medium without strong final-state interactions. Correlations of direct photons with low transverse momentum enable access to the spatio-temporal evolution of the emitting source via Hanbury Brown–Twiss (HBT) interferometry.
In this contribution, the measurement of direct-photon HBT with ALICE is investigated using the Photon Conversion Method (PCM). In this method photons are reconstructed from electron–positron pairs originating from conversions in the detector material, allowing for an excellent momentum resolution at low transverse momentum. Together with the increased data-taking rate thanks to the ALICE Run 3 detector upgrade, this enables such a measurement for the first time with the PCM technique and opens the prospect of three-dimensional direct-photon HBT measurements.
This poster presents the current status of the analysis with a focus on the correlated background of the direct-photon HBT analysis in Pb--Pb collisions at $\sqrt{s_\mathrm{NN}}$ = 5.36 TeV with ALICE in Run 3.
| Is this an experimental talk? | Yes |
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| 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 |