Isolated photon cross section in different energies and systems (QM2022)

Description

Plots compiling the preliminary and published results on isolated photons $p_{\rm T}$ spectra measured with the photon in EMCal in pp collisions at $\sqrt{s}=$  7, 8, 13 TeV and p-Pb collisions at $\sqrt{s_{\rm NN}}=$  5.02 TeV.

Ratios of pp collisions cross sections $\sqrt{s}$ = 13 TeV / $\sqrt{s}$ = 7 TeV,  $\sqrt{s}$ = 13 TeV / $\sqrt{s}$ = 8 TeV,  $\sqrt{s}$ = 8 TeV / $\sqrt{s}$ = 7 TeV.

All cross sections $p_{\rm T}$ spectra and their ratios are shown for ALICE measurement and NLO JETPHOX calculation with NNPDOF40, NLO calculations scaled down by the partonic to hadronic isolation efficiency $\kappa^{\rm iso}$.

Isolation energy ($p_{\rm T}^{\rm iso}$) change from isolation using only charged particles ($p_{\rm T}^{\rm iso,~ch}$ , pp $\sqrt{s}=$ 8, 13 TeV and  p-Pb $\sqrt{s_{\rm NN}}=$  5.02 TeV) and using neutral (calorimeter) and charged particle information (pp $\sqrt{s}=$  7 TeV), and subtracting the underlying event from the isolation energy (pp $\sqrt{s}$ = 8 TeV and  p-Pb $\sqrt{s_{\rm NN}}$ = 5.02 TeV) and not subtracting it ($p_{\rm T}^{\rm iso,~UE}$, pp $\sqrt{s}=$ 7, 13 TeV). Cone size is $R=0.4$ common to all systems.

Acceptance considered is also different depending the system, summary of differences between systems: