University Plymouth Seminar Abstract

Title: Observation of the Breit-Wheeler Process in Heavy-Ion Collisions Quantum electrodynamics (QED), the relativistic quantum field theory of electromagnetism, is the best tested theory in physics. Only a handful of fundamental interactions between light and matter are allowed by QED, almost all of which have been observed in the 80 or so years since their prediction. Only the Breit-Wheeler process, the simplest mechanism for converting ’light quanta’ into matter and antimatter, has eluded observation for decades.

In this talk I will present STAR measurements of e+e- pair production in ultra-peripheral and peripheral Au+Au collisions at sqrt(sNN) = 200 GeV. A comprehensive study of the pair kinematics is presented to distinguish the gamma gamma to e+ e- process from other possible production mechanisms and to definitively identify the Breit-Wheeler process for the first time. Furthermore, the measured distribution of electron-positron pairs reveals a striking fourth-order angular modulation which demonstrates the linear polarization of the colliding photons. I’ll end the talk by briefly discussing applications of these observations and open questions that may be possible to address with future measurements in heavy-ion collisions.

Similar to my [UIUC Experimental Nuclear Physics Faculty Position] abstract