Analysis of Photon Cross-section Spectra with Electromagnetic Calorimeter Energies

The Quark-Gluon Plasma is a topic that is prominent in High Energy Physics, particularly within studies of heavy ion collisions. One of the methods of studying the QGP is to look at how particles interact within the plasma. In heavy ion collisions, particles such as quarks, photons, and gluons are ejected from the initial collision in jets that are conic in shape, and have a radius. From these jets, we can determine particle energies, which is an important measurement to make as it can help us to characterize interactions within the QGP.

One of the instruments that will record this type of data is the sPHENIX detector at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. Photons deposit energy, and the EMCal towers, or cluster of towers, can record that energy. Photon energy and scattering interactions can also be theoretically determined using Leading Order calculations of differential cross-section that can be fit to the data that is to be measured with the detector. As sPHENIX is undergoing the commissioning process, it is necessary to be able to analyze the energies of individual towers, or tower clusters, of the sPHENIX EMCal to identify photon energies so that the performance for reconstruction and calibration of photon fragmentation from jets can be evaluated. The poster that is to be presented will show EMCal energies where photons have been detected and compare them to theoretically calculated photon cross-section spectra in order to contribute to the sPHENIX EMCal commissioning process and Jet Performance.