Title:FROM THE STARS TO STAR: Intensity Interferometry from HBT to Heavy Ions

Speaker: Mike Lisa (OSU)

Abstract: Sixty years ago, two radio engineers emerged from the frenzy of World War II and entered the new field of radio astronomy. Hanbury Brown and Twiss developed an entirely new instrument and technique, based on “correlated noise,” to measure the angular radius of previously un-resolvable stars. Initially greeted with skepticism, their work led directly to the birth of quantum optics. At nearly the same time, Goldhaber et al discovered a tiny unexpected correlation in the first true particle physics experiments; until recently, the “GGLP effect” played a minor role in particle physics. It would take another 15 years until the connection between these apparently disparate phenomena was realized by Shuryak, Gyulassy and others around 1976, just as the new field of heavy ion physics was emerging. Thus did Hanbury Brown’s discovery give birth to femtoscopy, the most direct method to probe the highly non-trivial dynamic space-time structure of a heavy ion collision. I will discuss the structures and insights that femtoscopy has revealed in ultra-relativistic ion collisions at RHIC and the LHC and how it is leading to a fresh look at high-energy proton collisions