Nuclear Particle Astrophysics (NPA) Seminar: Zhangbu Xu, BNL, “Probe extreme (peta-Tesla) electromagnetic field with Breit-Wheeler process”

Event time: 
Thursday, February 14, 2019 - 1:00pm to 2:00pm
Wright Lab (WNSL), 216 See map
272 Whitney Avenue
New Haven, CT 06511
Event description: 

We present first measurements of e^+e^- pair production from linearly polarized light-light scattering accompanying the creation of a Quark-Gluon Plasma in non-central high-energy heavy ion collisions. The yields peak distinctly at low transverse momentum between 40 to 60 MeV/c and show smooth mass distribution absent from any vector-meson contamination. The production can be explained quantitatively with exclusive Breit-Wheeler process, creating matter from pure lights. The measured pT distributions are significantly broader than model calculation for baseline ultra-peripheral collisions where hadronic interaction does not take place and are different between Au+Au and U+U collisions. Our experimental measurements with quantitative model calculations provide a possible tool to systematically study strong magnetic field at peta-Tesla scale controllable by varying the colliding impact parameter.

Host: Saehanseul Oh