Quark Matter 2014 - XXIV International Conference on Ultrarelativistic Nucleus-Nucleus Collisions

Search for intense magnetic field via dielectron asymmetry in Pb-Pb collisions at sNN = 2.76 TeV with ALICE at the LHC

20 May 2014, 16:30

2h

spectrum (darmstadtium)

Board: G-23

Poster Electromagnetic Probes Poster session

Speaker

Kenta Shigaki (Hiroshima University (JP))

Description

A very intense U(1) magnetic field is expected to be created in relativistic heavy-ion collisions. The field in non-central Pb-Pb collisions at the LHC energy should reach about ${10}^{14}$ T. It is not only the most intense in the universe, far beyond the field on the surfaces of magnetars ($\sim {10}^{11}$ T), but also is interesting in terms of fundamental physics as it is well above the critical magnetic field of electrons ($4\times {10}^9$ T) where non-linear behaviors of QED (e.g. photon splitting, real photons decaying into di-leptons, etc.) are theoretically expected. We have proposed new approaches to experimentally detect the field via a number of asymmetry measurements of dielectrons from direct virtual photons. The anisotropy of virtual photon decay, or the “polarization” of virtual photons, due to the field has been evaluated by QED calculations, and found possible to reach the order of ${10}^{-1}$. The status of the analysis in Pb-Pb collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}=2.76$ TeV at ALICE will be presented, along with details of the theoretical evaluations and physics discussions.

Presentation materials

Poster

qm14_20140520.pdf