I am giving a nuclear seminar on August 28 at BNL. 

 

Nuclear Physics Seminar

"Probe strong magnetic field in QGP with dielectrons from photon-photon interactions"

Presented by Zhangbu Xu, BNL

Tuesday, August 28, 2018, 11:00 am — Small Seminar Room, Bldg. 510

 

We presents first measurements of $e^+e^-$ pair production from light-light scattering in non-central heavy ion collisions. 

The excess yields peak distinctly at low transverse momentum with sqrt() between 40 to 60 MeV/c. 

The excess yields can be explained only when the photon-photon interactions are included in model calculations. 

However, the measured pT^2 distributions are significantly broader than model calculation and are different between Au+Au and U+U. 

Our measurements provide a possible experimental evidence of the existence of strong electromagnetic field with a magnetic rigidity 

of the order of 0.3 pion mass^2. 

And I will discuss its possible impact on emerging phenomena in hadronic heavy-ion collisions, such as Chiral Magnetic Effect.