Direct photon production and jet energy-loss in small systems

Abstract

Two types of penetrating probes, direct photon and QCD jets, are investigated in the background of a small and rapidly expanding droplet of quark-gluon plasma. The additional thermal electromagnetic radiation results in a $\sim$50\% enhancement of the direct photons. In high multiplicity p+Pb collisions, jets can lose a sizeable fraction of their initial energy, leading to a charged hadron $R_{\mathrm{pA}}$ of $\sim$0.8 at a transverse momentum around 10\,GeV. Those two proposed measurements can help understand the apparent collective behaviour observed in small collision systems.

4 pages. Contribution to the Proceedings of Quark Matter 2015, Kobe, Japan

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Cited by in corpus (3)

• The LPM effect in sequential bremsstrahlung 2: factorization
• Small system studies: A theory overview
• Early time dynamics and hard probes in heavy-ion collisions