Search for strong magnetic field via electron-pair asymmetry measurement in Au+Au at $\sqrt{s_{NN}}$ = 200 GeV at RHIC-PHENIX

20 May 2014, 16:30
spectrum (darmstadtium)



Board: C-06
Poster Initial State Physics Poster session


Mr TOMOYA HOSHINO (Hiroshima University)


Several models predict a strong magnetic field may be created in high-energy heavy-ion collisions by light-speed moving spectators and collision participants. The field can reach as high as $10^{14}$ teslas at RHIC, and rapidly decreases in a few fm/c. Such a strong field may exhibit charge distribution asymmetry with respect to the magnetic field direction that is orthogonal to the reaction plane, which has been investigated recently. According to theoretical calculation using vacuum polarization tensor in external magnetic field, virtual photon decay probability depends on the direction of strong field. This results in characteristic angular distributions of electron pairs with respect to the reaction plane. The effect is also dependent on centrality because the strength of the magnetic field changes over centralities. We look for the strong magnetic field effect via virtual photon decay, by taking advantage of an excellent electron-identification capability in PHENIX. Methods for background subtraction and signal extraction to detect the field are discussed.
On behalf of collaboration: PHENIX

Primary author

Mr TOMOYA HOSHINO (Hiroshima University)

Presentation Materials