17-24 July 2013
KTH and Stockholm University Campus
Europe/Stockholm timezone

Spectator charge splitting of directed flow in heavy ion collisions

18 Jul 2013, 10:08
E2 (KTH Campus)


KTH Campus

Talk presentation Ultrarelativistic Heavy Ions Ultrarelativistic Heavy Ions


Antoni Szczurek (Institute of Nuclear Physics)


We estimate the electromagnetic effect of the spectator charge on azimuthal anisotropies observed in heavy ion collisions. For peripheral Pb+Pb reactions at the top energy of the CERN Super Proton Synchrotron, $\sqrt{s_{NN}}=17.3$ GeV, we predict this effect to bring very large distortions to the observed directed flow, $v_1$, of positive and negative pions emitted close to beam rapidity. The overall magnitude of this effect is comparable to values of $v_1$ reported by the WA98 experiment. We argue that also at lower rapidities, the spectator induced electromagnetic effect may result in the splitting of values of $v_1$ observed for positive and negative pions. Such a splitting is visible also in the data reported by the STAR Collaboration from the RHIC Beam Energy Scan. Both effects are sensitive to the space-time scenario assumed for pion emission. Therefore, the electromagnetic splitting brings new information on the collision dynamics. The presentation will be based on our recent preprint [1]. 1) A. Rybicki and A. Szczurek, arXiv:1303.7354, submitted to Phys. Rev. {\bf C}.

Primary author

Antoni Szczurek (Institute of Nuclear Physics)


Dr Andrzej Rybicki (Institute of Nuclear Physics, Krakow)

Presentation Materials