Speaker
Description
Measurements of low $p_{\rm T}$ direct photon production at midrapidity in pp collisions at $\sqrt{s}=2.76$ and 8 TeV, as well as in p-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV were carried out by the ALICE experiment at the LHC. Photons were detected with either of the two electromagnetic calorimeters, EMCal and PHOS, and via reconstruction of $e^+e^-$ pairs from conversions in the ALICE detector material using the central tracking system. Where possible the results were combined for the inclusive photon spectra. An additional hybrid method, combining the conversion information with that of the calorimeters, was included in our best estimate of the direct photon excess ratio $R_{\gamma}$, as well as the extraction of direct photon spectra or their upper limits. Below $3$ GeV/$c$, $R_\gamma$ was found to be consistent with unity in all of the investigated collision systems. Furthermore, the direct photon spectra will be compared to pQCD next-to-leading order calculations.
| Content type | Experiment |
|---|---|
| Collaboration | ALICE |
| Centralised submission by Collaboration | Presenter name already specified |
