Speaker
Description
Direct photons produced in heavy ion collisions are penetrating probes and as such encode the entire space-time history of the collision, from the initial hard scattering to the final kinetic freeze-out, but their description is a major challenge to theoretical models, particularly to those that concentrate mostly on thermal radiation from the quark-gluon plasma and the hadron gas. Simultaneous observation of large yields and large azimuthal asymmetries (elliptic flow) by PHENIX has so far not been reproduced quantitatively, a situation dubbed "direct photon puzzle". Using the 2014 200 GeV Au+Au data, which has ten times the statistics of earlier published results, and employing one single analysis technique over a broad transverse momentum range of 0.8 - 10 GeV/c, PHENIX re-measured both the direct and nonprompt photon yields and the direct photon elliptic flow in finer centrality bins than previously published. Comparisons to recent models indicate that inclusion of novel mechanisms like magnetic emission and radiative hadronization might help resolve the direct photon puzzle.
Details
Ms. Melinda Orosz, University of Debrecen, Hungary, https://kisfiz.unideb.hu/
| Internet talk | No |
|---|---|
| Is this an abstract from experimental collaboration? | Yes |
| Name of experiment and experimental site | PHENIX |
| Is the speaker for that presentation defined? | Yes |
