English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We estimate the effect of the spectator-induced electromagnetic interactionon the directed flow of charged pions. For intermediate centrality Au+Aucollisions at $\sqrt{s_{NN}}=7.7$~GeV, we demonstrate that the electromagneticinteraction between spectator charges and final state pions results in chargesplitting of positive and negative pion directed flow. Such a charge splittingis visible in the experimental data reported by the STAR Collaboration.  The magnitude of this charge splitting appears to strongly depend on theactual distance between the pion emission site (pion at freeze-out) and thespectator system. As such, the above electromagnetic effect brings new,independent information on the space-time evolution of pion production in heavyion collisions.  From the comparison of our present analysis to our earlier studies made forpions produced at higher rapidity, we formulate conclusions on the rapiditydependence of the distance between the pion emission site and the spectatorsystem. This distance appears to decrease with increasing pion rapidity,reflecting the longitudinal expansion of the strongly-interacting systemresponsible for pion emission. Thus for the first time, information on thespace-time characteristics of the system is being provided by means of thespectator-induced electromagnetic interaction.  The above electromagnetic effect being in fact a straight-forward consequenceof the presence of spectator charges in the collision, we consider that itshould be considered as a baseline for studies of other phenomena, like thoserelated to the electric conductivity of the quark-gluon plasma.

Charge splitting of directed flow and space-time picture of pion emission from the electromagnetic interactions with spectators