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

by Zhangbu Xu (BNL)

Tuesday 28 Aug 2018, 11:00 → 13:00 US/Eastern

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(<pT^2>) 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. And I will discuss its possible impact on emerging phenomena in hadronic heavy-ion collisions, such as Chiral Magnetic Effect.

BField_lowpt_ee_BNLseminar_082018.pptx