Feasibility Study of Ultraperipheral Collision Physics in sPHENIX

Ultraperipheral Collisions (UPC's) are collisions where two ions in a collider are separated by more than twice the ion radius. Instead of a direct collision between the two ions, the particles interact via electromagnetic and photonuclear exchanges. The sPHENIX experiment is a new experiment at the Relativistic Heavy Ion Collider (RHIC) which has a high data acquisition (DAQ) rate capability. sPHENIX will collect significantly more data about the Quark Gluon Plasma, which is created in RHIC's particle smashups. To best exploit this capability, triggers need to be devised so that we can accurately identify special events such as the creation of UPC J/Psi particles and record those events. UPC collisions will allow us to study the gluon spatial distribution in the nuclei, as well as the nuclear gluon parton distribution and the gluon helicity flip Generalized Parton Distribution (GPD). The Heavy Ion Jet Interaction Generator (HIJING) is a Monte Carlo model event generator that is based on quantum chromodynamics (QCD) and studies jets and particle production in high energy proton- proton (pp), proton-nucleus (pA), and nucleus-nucleus (AA) collisions. HIJING is designed to explore a wide range of possible initial conditions that occur in RHIC. We did an initial study of the backgrounds using the Heavy Ion Jet Interaction Generator (HIJING) event generator. Very peripheral Au+Au events, of which HIJING simulates, could produce the same signature in sPHENIX as a UPC event, which only produces two tracks. Using Monte Carlo simulation, I identified UPC events within a run and background events that mimic UPC events, thus generating a good signal to noise ratio within this feasibility study.