Speaker
Description
Heavy-ion collisions produce a significant excess of low-$p_T$ direct photons that have a large $v_2$. Whether this strong direct photon signal can be explained by thermal photons radiated by the plasma depends critically on the value of the thermal photon emission rate. Building on published rate calculations from hadronic models, lattice QCD, perturbative QCD and holography, we systematically quantify the uncertainty of the photon rate as a function of the plasma's temperature and the photon's energy. Propagating these uncertainties to the photon spectrum and $v_n$'s using hydrodynamic simulations, we assess the impact on the photon puzzle under both optimistic and conservative uncertainty scenarios. We put forward a general framework that can update the rate's uncertainty using future calculations from lattice or other sources.
| Is this an experimental talk? | No |
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| Is this on behalf of a collaboration? | No |
| Are you willing to present as a poster if it is not selected for oral presentation? | Yes |